U.S. corporations have kept money earned overseas outside of the country for decades, to avoid paying taxes twice: once to the country where they earned the revenue, and once to the country they call home.
As of April 2017, the total was an unprecedented amount: $2.6 trillion, with a T. That's also T for Tim, Tim Cook. The CEO of Apple, Inc, the largest holder of cash, has acknowledged the company is keeping $231 billion in cash overseas to avoid paying the 35 percent corporate tax rate.