Deposits - Interest-bearing or Noninterest-bearing (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
U.S.:
Interest-bearing	$ 10,352,703	$ 10,393,449
Noninterest-bearing	5,067,812	5,368,729
Foreign:
Interest-bearing	783,721	748,678
Noninterest-bearing	653,010	639,212
Total deposits	$ 16,857,246	$ 17,150,068