Deposits - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deposits [Abstract]
Deposits	$ 24,283,983	$ 18,943,158
Brokered deposits	13,800,000	10,300,000
Retail and other deposits	10,500,000	8,600,000
Aggregate of deposits of individual depositors	6,800,000	5,900,000
Brokered deposit placement fee	18,000	13,000	$ 9,000
Third party broker fees paid	28,000	26,000	$ 12,000
Deposits exceeding FDIC insurance limits	963,000	523,000
Accrued interest on deposits	$ 68,000	$ 53,000