Deposits Deposits (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Interest checking deposits	$ 2,972,357	$ 2,711,250
Money market deposits	5,432,169	4,890,567
Savings deposits	571,422	690,353
Time deposits $250,000 and under	1,593,453	1,709,980
Time deposits over $250,000	412,185	355,342
Total interest-bearing deposits	$ 10,981,586	$ 10,357,492