Segment Information (Summary Of Financial Information By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net interest income	$ 228,763				$ 221,431
Provision for credit losses	4,804				0
Origination and sale	16,844				62,505
Servicing	9,140				9,087
Changes due to collection/realization of expected cash flows over time	(5,347)				(4,545)
Changes due to valuation inputs or assumptions	40,149				(2,014)
Gain on sale of debt securities, net	2				4
Loss on equity securities, net	(2,661)				(706)
Gain on swap derivatives, net	7,047				11,750
Change in fair value of certain loans held for investment	(21,049)				(510)
Non-interest income (excluding above items)	35,844				33,229
Noninterest Income	79,969				108,800
Merger related expenses	2,278				0
Exit and disposal costs	3,033				1,200
Non-interest expense (excluding above items)	177,119				186,392
Allocated expenses, net	0				0
Total non-interest expense	182,430				187,592
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	121,498				142,639
Provision for income taxes	30,341				34,902
Net income	91,157	$ 88,354	$ 108,066	$ 116,143	107,737
Total assets	30,637,126	30,640,936
Loans held for sale	309,946	353,105
Total loans and leases	22,975,761	22,553,180
Total deposits	26,699,587	26,594,685
Core Banking
Segment Reporting Information [Line Items]
Net interest income	227,087				217,574
Provision for credit losses	4,804				0
Origination and sale	0				0
Servicing	0				0
Changes due to collection/realization of expected cash flows over time	0				0
Changes due to valuation inputs or assumptions	0				0
Gain on sale of debt securities, net	2				4
Loss on equity securities, net	(2,661)				(706)
Gain on swap derivatives, net	7,047				11,750
Change in fair value of certain loans held for investment	(21,049)				(510)
Non-interest income (excluding above items)	35,650				32,913
Noninterest Income	18,989				43,451
Merger related expenses	2,278				0
Exit and disposal costs	3,033				1,200
Non-interest expense (excluding above items)	148,423				145,161
Allocated expenses, net	3,735				(790)
Total non-interest expense	157,469				145,571
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	83,803				115,454
Provision for income taxes	20,917				28,106
Net income	62,886				87,348
Total assets	30,153,079	30,155,058
Loans held for sale	0	0
Total loans and leases	22,975,761	22,553,180
Total deposits	26,479,078	26,370,568
Mortgage Banking
Segment Reporting Information [Line Items]
Net interest income	1,676				3,857
Provision for credit losses	0				0
Origination and sale	16,844				62,505
Servicing	9,140				9,087
Changes due to collection/realization of expected cash flows over time	(5,347)				(4,545)
Changes due to valuation inputs or assumptions	40,149				(2,014)
Gain on sale of debt securities, net	0				0
Loss on equity securities, net	0				0
Gain on swap derivatives, net	0				0
Change in fair value of certain loans held for investment	0				0
Non-interest income (excluding above items)	194				316
Noninterest Income	60,980				65,349
Merger related expenses	0				0
Exit and disposal costs	0				0
Non-interest expense (excluding above items)	28,696				41,231
Allocated expenses, net	(3,735)				790
Total non-interest expense	24,961				42,021
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	37,695				27,185
Provision for income taxes	9,424				6,796
Net income	28,271				$ 20,389
Total assets	484,047	485,878
Loans held for sale	309,946	353,105
Total loans and leases	0	0
Total deposits	$ 220,509	$ 224,117