Share-based Compensation and Other Employment Benefit Plans - Expenses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Salaries and other personnel expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense included in non-interest expense	$ 26,957	$ 17,827	$ 19,618
Merger-related expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense included in non-interest expense	0	0	4,219
Other operating expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense included in non-interest expense	838	814	650
Non-interest expense
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense included in non-interest expense	$ 27,795	$ 18,641	$ 24,487