Securities (Tables)

3 Months Ended

Mar. 31, 2019

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 Securities Available for Sale

Securities Available for Sale
(in thousands)	March 31, 2019								December 31, 2018
			Gross		Gross						Gross
	Amortized		Unrealized		Unrealized		Fair		Amortized		Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value		Cost		Gains		Losses		Value
U.S. Treasury and government agency securities	$	73,426		—		1,283	$	72,143	$	74,339	$	—	$	2,633	$	71,706
Municipal obligations		245,707		1,833		1,600		245,940		246,713		360		6,646		240,427
Residential mortgage-backed securities		1,418,881		9,964		15,813		1,413,032		1,468,912		4,284		29,794		1,443,402
Commercial mortgage-backed securities		798,447		4,594		15,207		787,834		799,060		1,953		30,936		770,077
Collateralized mortgage obligations		158,904		1,212		1,485		158,631		163,282		903		2,260		161,925
Corporate debt securities		3,500		—		—		3,500		3,500		—		—		3,500
	$	2,698,865	$	17,603	$	35,388	$	2,681,080	$	2,755,806	$	7,500	$	72,269	$	2,691,037

Amortized Cost and Fair Value of Securities Held to Maturity

	March 31, 2019								December 31, 2018
			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	$	50,000		—		317	$	49,683	$	50,000	$	—	$	478	$	49,522
Municipal obligations		676,651		11,247		1,726		686,172		688,201		2,347		9,503		681,045
Residential mortgage-backed securities		613,964		3,701		3,148		614,517		640,393		1,461		6,117		635,737
Commercial mortgage-backed securities		356,919		1,233		3,780		354,372		357,175		376		10,882		346,669
Collateralized mortgage obligations		1,198,908		3,285		14,027		1,188,166		1,243,778		1,598		22,493		1,222,883
	$	2,896,442	$	19,466	$	22,998	$	2,892,910	$	2,979,547	$	5,782	$	49,473	$	2,935,856

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	$	368	$	374
Due after one year through five years		107,225		108,866
Due after five years through ten years		1,184,905		1,175,070
Due after ten years		1,406,367		1,396,770
Total available for sale debt securities	$	2,698,865	$	2,681,080

Securities with Unrealized Losses

Available for Sale
March 31, 2019	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	$	-		-		72,143		1,283	$	72,143	$	1,283
Municipal obligations		2,270		40		106,042		1,560		108,312		1,600
Residential mortgage-backed securities		640		6		852,716		15,807		853,356		15,813
Commercial mortgage-backed securities		-		-		583,978		15,207		583,978		15,207
Collateralized mortgage obligations		-		-		108,798		1,485		108,798		1,485
	$	2,910	$	46	$	1,723,677	$	35,342	$	1,726,587	$	35,388

Available for Sale
December 31, 2018	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	$	—		—	$	71,706	$	2,633	$	71,706	$	2,633
Municipal obligations		41,203		591		170,883		6,054		212,086		6,645
Residential mortgage-backed securities		305,090		2,485		762,826		27,309		1,067,916		29,794
Commercial mortgage-backed securities		96,226		1,851		570,485		29,085		666,711		30,936
Collateralized mortgage obligations		254		1		111,804		2,259		112,058		2,260
	$	442,773	$	4,928	$	1,687,704	$	67,340	$	2,130,477	$	72,268

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	$	80,915	$	80,716
Due after one year through five years		67,617		67,418
Due after five years through ten years		1,392,654		1,398,880
Due after ten years		1,355,256		1,345,896
Total held to maturity securities	$	2,896,442	$	2,892,910

Securities with Unrealized Losses

Held to Maturity
March 31, 2019	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	$	—		—	$	49,682	$	317	$	49,682	$	317
Municipal obligations		8,750		63		169,931		1,663		178,681		1,726
Residential mortgage-backed securities		—		—		186,221		3,148		186,221		3,148
Commercial mortgage-backed securities		—		—		312,296		3,780		312,296		3,780
Collateralized mortgage obligations		—		—		860,183		14,027		860,183		14,027
	$	8,750	$	63	$	1,578,313	$	22,935	$	1,587,063	$	22,998
Held to Maturity
December 31, 2018	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	$	—	$	—	$	49,521	$	478	$	49,521	$	478
Municipal obligations		233,469		2,256		233,280		7,247		466,749		9,503
Residential mortgage-backed securities		90,730		123		235,251		5,994		325,981		6,117
Commercial mortgage-backed securities		—		—		305,419		10,882		305,419		10,882
Collateralized mortgage obligations		77,394		281		897,153		22,212		974,547		22,493
	$	401,593	$	2,660	$	1,720,624	$	46,813	$	2,122,217	$	49,473