Securities (Tables)

6 Months Ended

Jun. 30, 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

	June 30, 2021								December 31, 2020
			Gross		Gross						Gross			Gross
Securities Available for Sale	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	$	398,742	$	6,450	$	1,046	$	404,146	$	207,365	$	6,289	$	284	$	213,370
Municipal obligations		306,803		14,912		2,420		319,295		309,342		17,536		153		326,725
Residential mortgage-backed securities		3,457,426		44,662		30,538		3,471,550		2,560,249		69,570		8		2,629,811
Commercial mortgage-backed securities		2,865,057		96,868		23,329		2,938,596		2,323,306		135,516		3,288		2,455,534
Collateralized mortgage obligations		147,633		4,421		—		152,054		354,472		7,651		—		362,123
Corporate debt securities		14,500		280		—		14,780		11,500		264		—		11,764
	$	7,190,161	$	167,593	$	57,333	$	7,300,421	$	5,766,234	$	236,826	$	3,733	$	5,999,327

Amortized Cost and Fair Value of Debt Securities Held to Maturity

	June 30, 2021								December 31, 2020
			Gross		Gross						Gross			Gross
Securities Held to Maturity	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	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Municipal obligations		619,970		43,791		146		663,615		627,019		51,408		2		678,425
Residential mortgage-backed securities		50,038		1,139		170		51,007		21,951		1,469		—		23,420
Commercial mortgage-backed securities		574,389		41,052		246		615,195		549,686		54,587		—		604,273
Collateralized mortgage obligations		88,315		1,975		—		90,290		158,514		2,949		—		161,463
	$	1,332,712	$	87,957	$	562	$	1,420,107	$	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 gain on, and gross losses on sales of securities during the six months ended June 30, 2021 and 2020.

	Six Months Ended June 30,
(in thousands)	2021		2020
Proceeds	$	198,681	$	124,122
Gross gains		1,649		1,082
Gross losses		1,316		970
Net gain	$	333	$	112

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

Debt Securities Available for Sale	Amortized		Fair
(in thousands)	Cost		Value
Due in one year or less	$	2,204	$	2,210
Due after one year through five years		367,341		390,607
Due after five years through ten years		3,042,604		3,113,151
Due after ten years		3,778,012		3,794,453
Total available for sale debt securities	$	7,190,161	$	7,300,421

Securities with Unrealized Losses

Available for Sale
June 30, 2021	Losses < 12 months				Losses 12 months or >				Total
(in thousands)	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
U.S. Treasury and government agency securities	$	108,890	$	1,046	$	—	$	—	$	108,890	$	1,046
Municipal obligations		69,307		2,420		—		—		69,307		2,420
Residential mortgage-backed securities		1,739,131		30,534		719		4		1,739,850		30,538
Commercial mortgage-backed securities		1,079,547		23,329		—		—		1,079,547		23,329
Collateralized mortgage obligations		—		—		—		—		—		—
Corporate debt securities		1,500		—		—		—		1,500		—
	$	2,998,375	$	57,329	$	719	$	4	$	2,999,094	$	57,333

Available for Sale
December 31, 2020	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

Debt Securities Held to Maturity	Amortized		Fair
(in thousands)	Cost		Value
Due in one year or less	$	10,341	$	10,505
Due after one year through five years		243,443		258,189
Due after five years through ten years		644,987		694,204
Due after ten years		433,941		457,209
Total held to maturity securities	$	1,332,712	$	1,420,107

Securities with Unrealized Losses

Held to maturity
June 30, 2021	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		7,854		146		191		—		8,045		146
Residential mortgage-backed securities		8,127		170		—		—		8,127		170
Commercial mortgage-backed securities		12,073		246		—		—		12,073		246
Collateralized mortgage obligations		1,738		—		—		—		1,738		—
	$	29,792	$	562	$	191	$	—	$	29,983	$	562

Held to maturity
December 31, 2020	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