What do personal finances look like for someone worth billions? The Epstein files provide a rare look.

The complex finances of former Apollo Global Management Chief Executive Officer Leon Black are laid out in several documents in the Justice Department’s recent releases , down to the exact balances in each of his 69 bank accounts and the details of a $484 million loan backed by his extensive art collection. Black socialized with Jeffrey Epstein and turned to him for tax- and estate-planning advice.

The documents date to 2014 and 2015, so Black’s finances are different today. But the disclosures offer an exceptionally granular look at the strategies used by many of the ultrarich to build wealth and minimize their tax bills.

Some of the richest Americans borrow, even though they are worth billions on paper. They use trusts and limited liability companies and put their money into private investments that aren’t accessible to the typical person. And they spend millions of dollars on things like rare books and Chinese bronzes.

Black’s net worth was estimated at $5 billion, according to a “Financial Analysis Summary” dated March 31, 2015. The documents don’t make clear who prepared the summary or for what purpose.

Business investments including his Apollo shares and stakes in Apollo funds accounted for $2.3 billion of his assets. His art collection, rare-book collection and other personal items were worth $2.8 billion. He also had seven homes, 11 cars, a Gulfstream jet and a Benetti yacht.

Black, now 74 years old, owns about 7% of Apollo, which manages $938 billion in assets across private credit and private equity and owns a large life insurer. The firm’s shares are up 10-fold in the past decade. Forbes estimates his net worth is now about $14 billion.

Black stepped down from the CEO role in 2021 after a review by an outside law firm hired by Apollo found he had paid Epstein $158 million for his services. The review by Dechert found no evidence that Black was involved in the criminal activities of Epstein, who was indicted in 2019 on federal sex-trafficking charges involving underage girls.

A spokesman for Black declined to comment for this article. Black has previously said he paid Epstein for estate planning, tax work, structuring of art entities and philanthropic advice from 2012 to 2017. He said he didn’t engage in wrongdoing, decided to give Epstein a second chance after his 2008 conviction for soliciting prostitution from a teenage girl, and regrets his involvement with Epstein.

Here are some notable aspects of Black’s finances laid out in the documents:

More than $150 million in cash

Leon Black kept $154 million in cash across his dozens of bank accounts, according to the March 2015 financial summary. Some of the accounts are listed as having his or his wife’s name on them, while others are in the names of trusts or LLCs affiliated with the Blacks.

The financial statement lists more than a dozen trusts. Investigators for Senate Finance Committee Ranking Member Ron Wyden (D., Ore.) are looking into Black’s tax strategies and dealings with Epstein, including the use of trusts.

Black spread out his bank accounts, keeping accounts at lenders including Bank of America, JPMorgan Chase, Deutsche Bank and Wells Fargo.

Even a billionaire couldn’t get any interest on a checking account during this period, when the Federal Reserve kept rates near zero following the 2008-09 financial crisis. The highest rate the Blacks earned was 0.15%.

The family’s life was expensive. The Black family spent $1.2 million over the course of two months of 2015, according to a summary of the household’s expenses prepared by a company that helps wealthy families track their finances. This includes $27,000 on dining out, $35,000 on clothing and $67,000 on wine and liquor. They paid nearly $48,000 for landscaping at their Hamptons home during this two-month period.

The family committed to making $70 million in charitable donations in cash, according to another summary of their financials dated the end of September 2014.

Stock and hard-to-sell investments

More than $2 billion of Black’s wealth was tied up in Apollo stock, according to the September 2014 summary. The founders of the biggest private-equity firms seldom sell their shares, hanging on to them as a vote of confidence in their companies. Plus, selling long-held stock could incur big capital-gains taxes.

Black also had $126 million of “Apollo-related investments,” most of which appear to be investments in specific funds and companies, according to the September 2014 summary.

This document also shows millions of dollars of investments in private-equity funds and entities not connected to Apollo. One non-Apollo investment was a $34 million stake in a for-profit education company co-founded by Michael Milken, whom Black previously worked with at the now-defunct investment bank Drexel Burnham Lambert. Black also owned a $250,000 stake in Kappo Masa, a high-end sushi restaurant in New York City.

Some of Black’s outside investments were in funds focused on investing in timber, venture capital and Chinese private equity—areas not generally in Apollo’s wheelhouse at the time.

Black’s portfolio of “marketable securities,” which included mostly blue-chip names such as United Rentals, Disney, Coca-Cola and Boeing, was valued at only $13 million, according to the 2014 document.

A $484 million art loan

Black also had a $484 million loan from Bank of America backed by his extensive art collection, according to the March 2015 document. The loan was secured by paintings from artists including Edgar Degas, Paul Cézanne and Pablo Picasso, according to a May 2015 loan document.

Black is a prolific art collector who bought Edvard Munch’s “The Scream” at auction for nearly $120 million in 2012. He also had a book collection valued at $82 million (he bought a rare Babylonian Talmud later in 2015 for over $9 million) and Chinese bronzes worth $335 million, according to the March 2015 document.

Borrowing has gained popularity with the ultrawealthy, who often have much of their assets tied up in investments like private-equity holdings or shares in the companies they founded. Tapping loans for their expenses can come with big tax advantages, allowing them to avoid incurring capital-gains taxes by selling holdings.

“Rich people think of debt very differently than poor people do,” said Ed McCaffery, a University of Southern California law professor who has studied the finances of the wealthy. “It’s no less of a spectacular Monet if it happens to have a $10 million debt on it.”

Important customers can often get rock-bottom rates from banks. The variable rate at the time on Black’s art loan was 1.43%. While he owned his homes outright, Bank of America also lent him money at under 2% to buy his boat and plane.

Other banks were interested in lending Black even more. Deutsche Bank proposed giving Black an additional $500 million loan backed by art and Apollo shares, according to a document that appears to be from 2013. The document described Epstein as “Black’s estate/tax planning attorney” (Epstein didn’t have a law degree) and said the banker involved “has previously worked with Epstein on mutual clients.” The document said Black’s representatives hadn’t yet provided his financial statements.

Deutsche Bank played a key role in Epstein’s financial dealings in the years before his 2019 arrest.

Write to Rachel Louise Ensign at Rachel.Ensign@wsj.com and Miriam Gottfried at Miriam.Gottfried@wsj.com