Securities (Tables)

12 Months Ended

Dec. 31, 2021

Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]

Amortized Cost and Fair Value of Debt Securities Available for Sale

Securities Available for Sale
	December 31, 2021								December 31, 2020
			Gross		Gross						Gross		Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
(in thousands)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury and government agency    securities	$	420,857	$	3,781	$	5,340	$	419,298	$	207,365	$	6,289	$	284	$	213,370
Municipal obligations		304,536		13,184		3,562		314,158		309,342		17,536		153		326,725
Residential mortgage-backed securities		3,056,763		29,158		50,123		3,035,798		2,560,249		69,570		8		2,629,811
Commercial mortgage-backed securities		3,064,828		61,645		48,614		3,077,859		2,323,306		135,516		3,288		2,455,534
Collateralized mortgage obligations		119,046		1,837		—		120,883		354,472		7,651		—		362,123
Corporate debt securities		18,500		210		8		18,702		11,500		264		—		11,764
	$	6,984,530	$	109,815	$	107,647	$	6,986,698	$	5,766,234	$	236,826	$	3,733	$	5,999,327

Amortized Cost and Fair Value of Debt Securities Held to Maturity

Securities Held to Maturity
	December 31, 2021								December 31, 2020
			Gross		Gross						Gross		Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
(in thousands)	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury and government agency    securities	$	14,857	$	—	$	20	$	14,837	$	—	$	—	$	—	$	-
Municipal obligations		621,405		37,941		205		659,141		627,019		51,408		2		678,425
Residential mortgage-backed securities		268,907		682		1,499		268,090		21,951		1,469		—		23,420
Commercial mortgage-backed securities		603,156		28,679		669		631,166		549,686		54,587		—		604,273
Collateralized mortgage obligations		57,426		822		—		58,248		158,514		2,949		—		161,463
	$	1,565,751	$	68,124	$	2,393	$	1,631,482	$	1,357,170	$	110,413	$	2	$	1,467,581

Proceeds from Gross Gains on and Gross Losses on Sale of Securities

The following table presents the proceeds from, gross gains on, and gross losses on sales of securities during the years ended December 31, 2021, 2020 and 2019:

	Years Ended December 31,
(in thousands)	2021		2020		2019
Proceeds	$	198,681	$	211,919	$	268,413
Gross gains		1,649		1,984		—
Gross losses		1,316		1,496		—

Available for Sale Securities [Member]

Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]

Amortized Cost and Fair Value of Debt Securities by Contractual Maturity

(in thousands)	Amortized Cost		Fair Value
Debt Securities Available for Sale
Due in one year or less	$	2,387	$	2,403
Due after one year through five years		669,087		696,513
Due after five years through ten years		2,995,387		3,002,023
Due after ten years		3,317,669		3,285,759
Total available for sale debt securities	$	6,984,530	$	6,986,698

Securities with Unrealized Losses

Available for sale
	Losses < 12 Months				Losses 12 Months or >				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(in thousands)	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury and government agency securities	$	198,318	$	2,305	$	63,534	$	3,035	$	261,852	$	5,340
Municipal obligations		43,021		2,372		25,126		1,190		68,147		3,562
Residential mortgage-backed securities		1,293,179		20,581		819,596		29,541		2,112,775		50,122
Commercial mortgage-backed securities		786,206		14,819		665,687		33,796		1,451,893		48,615
Collateralized mortgage obligations		—		—		—		—		—		—
Corporate debt securities		6,992		8		—		—		6,992		8
.	$	2,327,716	$	40,085	$	1,573,943	$	67,562	$	3,901,659	$	107,647

Available for sale
	Losses < 12 Months				Losses 12 Months or >				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(in thousands)	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury and government agency securities	$	35,845	$	284	$	—	$	—	$	35,845	$	284
Municipal obligations		30,170		153		—		—		30,170		153
Residential mortgage-backed securities		530		2		760		6		1,290		8
Commercial mortgage-backed securities		446,190		3,288		—		—		446,190		3,288
Collateralized mortgage obligations		70		—		—		—		70		—
Corporate debt securities		2,000		—		—		—		2,000		—
	$	514,805	$	3,727	$	760	$	6	$	515,565	$	3,733

Held-to-maturity Securities [Member]

Schedule Of Gain Loss On Investments Including Marketable Securities And Investments Held At Cost Income Statement Reported Amounts Summary [Line Items]

Amortized Cost and Fair Value of Debt Securities by Contractual Maturity

(in thousands)	Amortized Cost		Fair Value
Debt Securities Held to Maturity
Due in one year or less	$	11,225	$	11,311
Due after one year through five years		361,412		377,421
Due after five years through ten years		618,557		650,531
Due after ten years		574,557		592,219
Total held to maturity debt securities	$	1,565,751	$	1,631,482

Securities with Unrealized Losses

Held to maturity
	Losses < 12 Months				Losses 12 Months or >				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(in thousands)	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury and government agency securities	$	14,837	$	20	$	—	$	—	$	14,837	$	20
Municipal obligations		7,795		205		—		—		7,795		205
Residential mortgage-backed securities		253,661		1,499		—		—		253,661		1,499
Commercial mortgage-backed securities		56,366		205		11,837		464		68,203		669
Collateralized mortgage obligations		—		—		—		—		—		—
	$	332,659	$	1,929	$	11,837	$	464	$	344,496	$	2,393

Held to maturity
	Losses < 12 Months				Losses 12 Months or >				Total
			Gross				Gross				Gross
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(in thousands)	Value		Losses		Value		Losses		Value		Losses
U.S. Treasury and government agency securities	$	—	$	—	$	—	$	—	$	—	$	—
Municipal obligations		—		—		2,381		2		2,381		2
Residential mortgage-backed securities		—		—		—		—		—		—
Commercial mortgage-backed securities		—		—		—		—		—		—
Collateralized mortgage obligations		—		—		—		—		—		—
	$	—	$	—	$	2,381	$	2	$	2,381	$	2