Other Noninterest Income and Expense (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($) bankingCenter	Dec. 31, 2020 USD ($) bankingCenter	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Other Income and Expenses [Abstract]
Gain on branch sales	$ 14,717		$ 0	$ 0
Termination of interest rate swaps	0		(17,302)	0
Loan servicing rights impairment	(17,605)	$ (17,605)	(3,882)	0
Other	49,430		42,995	28,769
Total other noninterest income	$ 46,542	46,542	21,811	28,769
Outside processing		60,650	38,151	20,574
Loan and lease expense		29,386	22,557	13,649
Professional fees		26,077	26,863	21,529
Advertising and marketing		25,854	28,220	28,120
FDIC insurance		23,893	18,298	15,056
Card processing and issuance costs		24,363	21,235	17,461
CFPB and OCC settlement charge		0	0	32,000	[1]
Other		142,528	148,392	107,097
Total other noninterest expense		$ 332,751	$ 303,716	$ 255,486
Number of branch sales | bankingCenter	7	7

[1] Year Ended December 31, (In thousands)202020192018 Other Noninterest Income Gain on branch sales(1) $14,717 $— $— Termination of interest rate swaps— (17,302)—  Loan servicing rights impairment (17,605)(3,882)—  Other 49,430 42,995 28,769 Total other noninterest income$46,542 $21,811 $28,769  Other Noninterest Expense Outside processing$60,650 $38,151 $20,574 Loan and lease expense29,386 22,557 13,649 Professional fees26,077 26,863 21,529 Advertising and marketing25,854 28,220 28,120 FDIC insurance23,893 18,298 15,056 Card processing and issuance costs24,363 21,235 17,461 CFPB and OCC settlement charge— — 32,000 Other142,528 148,392 107,097 Total other noninterest expense$332,751 $303,716 $255,486