Segment Information (Summary Of Financial Information By Reportable Segment) (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Net interest income	$ 248,170				$ 229,763		$ 476,933	$ 451,194
Provision (recapture) for credit losses	18,692				(22,996)		23,496	(22,996)
Origination and sale	15,101				41,367		31,945	103,872
Servicing	9,505				9,120		18,645	18,207
Changes due to collection/realization of expected cash flows over time	(4,961)				(4,366)		(10,308)	(8,911)
Changes due to valuation inputs or assumptions	10,899				(1,678)		51,048	(3,692)
Gain on sale of debt securities, net	0				0		2	4
(Loss) gain on equity securities, net	(2,075)				4		(4,736)	(702)
Gain on swap derivatives, net	7,337				(4,481)		14,384	7,269
Change in fair value of certain loans held for investment	(15,210)				2,782		(36,259)	2,272
Non-interest income (excluding above items)	34,639				48,327		70,483	81,556
Noninterest Income	55,235				91,075		135,204	199,875
Merger related expenses	2,672				0		4,950	0
Exit and disposal costs	442				4,728		3,475	5,928
Non-interest expense (excluding above items)	176,460				184,672		353,579	371,064
Allocated expenses, net	0				0		0	0
Total non-interest expense	179,574				189,400		362,004	376,992
Income before provision for income taxes	105,139				154,434		226,637	297,073
Provision for income taxes	26,548				38,291		56,889	73,193
Net income	78,591	$ 91,157	$ 88,354	$ 108,066	116,143	$ 107,737	169,748	223,880
Total assets	30,135,694		30,640,936				30,135,694
Loans held for sale	228,889		353,105				228,889
Total loans and leases	24,432,678		22,553,180				24,432,678
Total deposits	26,132,423		26,594,685				26,132,423
Core Banking
Segment Reporting Information [Line Items]
Net interest income	247,009				226,915		474,096	444,489
Provision (recapture) for credit losses	18,692				(22,996)		23,496	(22,996)
Origination and sale	0				0		0	0
Servicing	0				0		0	0
Changes due to collection/realization of expected cash flows over time	0				0		0	0
Changes due to valuation inputs or assumptions	0				0		0	0
Gain on sale of debt securities, net							2	4
(Loss) gain on equity securities, net	(2,075)				4		(4,736)	(702)
Gain on swap derivatives, net	7,337				(4,481)		14,384	7,269
Change in fair value of certain loans held for investment	(15,210)				2,782		(36,259)	2,272
Non-interest income (excluding above items)	34,461				48,151		70,111	81,064
Noninterest Income	24,513				46,456		43,502	89,907
Merger related expenses	2,672				0		4,950	0
Exit and disposal costs	442				4,728		3,475	5,928
Non-interest expense (excluding above items)	148,946				146,877		297,369	292,038
Allocated expenses, net	3,702				970		7,437	180
Total non-interest expense	155,762				152,575		313,231	298,146
Income before provision for income taxes	97,068				143,792		180,871	259,246
Provision for income taxes	24,530				35,630		45,447	63,736
Net income	72,538				108,162		135,424	195,510
Total assets	29,721,590		30,155,058				29,721,590
Loans held for sale	0		0				0
Total loans and leases	24,432,678		22,553,180				24,432,678
Total deposits	25,925,294		26,370,568				25,925,294
Mortgage Banking
Segment Reporting Information [Line Items]
Net interest income	1,161				2,848		2,837	6,705
Provision (recapture) for credit losses	0				0		0	0
Origination and sale	15,101				41,367		31,945	103,872
Servicing	9,505				9,120		18,645	18,207
Changes due to collection/realization of expected cash flows over time	(4,961)				(4,366)		(10,308)	(8,911)
Changes due to valuation inputs or assumptions	10,899				(1,678)		51,048	(3,692)
Gain on sale of debt securities, net							0	0
(Loss) gain on equity securities, net	0				0		0	0
Gain on swap derivatives, net	0				0		0	0
Change in fair value of certain loans held for investment	0				0		0	0
Non-interest income (excluding above items)	178				176		372	492
Noninterest Income	30,722				44,619		91,702	109,968
Merger related expenses	0				0		0	0
Exit and disposal costs	0				0		0	0
Non-interest expense (excluding above items)	27,514				37,795		56,210	79,026
Allocated expenses, net	(3,702)				(970)		(7,437)	(180)
Total non-interest expense	23,812				36,825		48,773	78,846
Income before provision for income taxes	8,071				10,642		45,766	37,827
Provision for income taxes	2,018				2,661		11,442	9,457
Net income	6,053				$ 7,981		34,324	$ 28,370
Total assets	414,104		485,878				414,104
Loans held for sale	228,889		353,105				228,889
Total loans and leases	0		0				0
Total deposits	$ 207,129		$ 224,117				$ 207,129