Deposits - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Deposits	$ 22,666,039	$ 24,283,983
Brokered deposits	11,900,000	13,800,000
Retail and other deposits	10,800,000	10,500,000
Aggregate of deposits of individual depositors	7,100,000	6,800,000
Brokered deposit placement fee	19,000	18,000	$ 13,000
Third party broker fees paid	5,000	28,000	$ 26,000
Deposits exceeding FDIC insurance limits	571,000	963,000
Accrued interest on deposits	$ 50,000	$ 68,000