Derivative Financial Instruments - Derivative Financial Instruments and the Amount and Location of the Net Gains or Losses Recognized in the Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments Gain Loss [Line Items]
Net gains (losses) recognized in the statements of income	$ 5,875	$ 11,271
Interest Rate Lock Commitments | Mortgage Banking Income
Derivative Instruments Gain Loss [Line Items]
Net gains (losses) recognized in the statements of income	773	6,303
Forward Commitments | Mortgage Banking Income
Derivative Instruments Gain Loss [Line Items]
Net gains (losses) recognized in the statements of income	3,227	(2,184)
Interest Rate Swap Agreements | Other Noninterest Income
Derivative Instruments Gain Loss [Line Items]
Net gains (losses) recognized in the statements of income	1,604	6,438
Foreign Exchange Contracts | Other Noninterest Income
Derivative Instruments Gain Loss [Line Items]
Net gains (losses) recognized in the statements of income	$ 271	$ 714