Commitments and Contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Guarantor Obligations [Line Items]
Amortization Method Qualified Affordable Housing Project Investments	$ 163,900	$ 167,800
FDIC shared-loss payable	15,601	112,395	$ 105,618
Commitments to Extend Credit
Guarantor Obligations [Line Items]
Unused Commitments to Extend Credit	12,098,417	10,682,378
Amortization Method Qualified Affordable Housing Project Investments	53,700	70,000
Standby Letters of Credit
Guarantor Obligations [Line Items]
Affordable Housing Program Obligation	$ 129,819	$ 99,601