Securities (Tables)

3 Months Ended

Mar. 31, 2023

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

	March 31, 2023								December 31, 2022
			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	$	113,016	$	287	$	1,788	$	111,515	$	113,211	$	—	$	2,346	$	110,865
Municipal obligations		206,219		247		1,997		204,469		207,014		59		3,981		203,092
Residential mortgage-backed securities		2,583,935		240		364,911		2,219,264		2,655,381		224		398,619		2,256,986
Commercial mortgage-backed securities		3,239,281		2,899		299,575		2,942,605		3,234,278		2,032		342,880		2,893,430
Collateralized mortgage obligations		72,884		—		5,241		67,643		76,830		—		6,242		70,588
Corporate debt securities		23,500		—		3,376		20,124		23,500		—		2,420		21,080
	$	6,238,835	$	3,673	$	676,888	$	5,565,620	$	6,310,214	$	2,315	$	756,488	$	5,556,041

Amortized Cost and Fair Value of Debt Securities Held to Maturity

	March 31, 2023								December 31, 2022
			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	$	427,643	$	824	$	41,538	$	386,929	$	426,454	$	21	$	49,044	$	377,431
Municipal obligations		696,471		1,987		19,262		679,196		698,908		753		26,558		673,103
Residential mortgage-backed securities		715,499		—		63,526		651,973		734,478		—		72,532		661,946
Commercial mortgage-backed securities		944,292		—		77,653		866,639		948,691		—		87,211		861,480
Collateralized mortgage obligations		41,159		—		2,136		39,023		43,964		—		2,526		41,438
	$	2,825,064	$	2,811	$	204,115	$	2,623,760	$	2,852,495	$	774	$	237,871	$	2,615,398

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 three months ended March 31, 2023 and 2022. Net gains or losses are reflected in the "Securities transactions, net" line item on the Consolidated Statements of Income.

	Three Months Ended  March 31,
($ in thousands)	2023		2022
Proceeds	$	—	$	73,219
Gross gains		—		—
Gross losses		—		87
Net gain (loss)	$	—	$	(87	)

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	$	72	$	72
Due after one year through five years		1,024,989		979,364
Due after five years through ten years		2,980,929		2,699,847
Due after ten years		2,232,845		1,886,337
Total available for sale debt securities	$	6,238,835	$	5,565,620

Securities with Unrealized Losses

Available for Sale
March 31, 2023	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	$	49,332	$	382	$	8,070	$	1,406	$	57,402	$	1,788
Municipal obligations		85,570		649		86,444		1,348		172,014		1,997
Residential mortgage-backed securities		137,406		4,437		2,071,526		360,474		2,208,932		364,911
Commercial mortgage-backed securities		318,876		14,695		2,570,771		284,880		2,889,647		299,575
Collateralized mortgage obligations		—		—		67,643		5,241		67,643		5,241
Corporate debt securities		1,820		180		17,804		3,196		19,624		3,376
	$	593,004	$	20,343	$	4,822,258	$	656,545	$	5,415,262	$	676,888

Available for Sale
December 31, 2022	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	$	102,607		754	$	8,258	$	1,592	$	110,865	$	2,346
Municipal obligations		192,334		3,981		—		—		192,334		3,981
Residential mortgage-backed securities		636,060		49,790		1,611,832		348,829		2,247,892		398,619
Commercial mortgage-backed securities		1,489,974		114,195		1,351,530		228,685		2,841,504		342,880
Collateralized mortgage obligations		41,703		3,275		28,884		2,967		70,587		6,242
Corporate debt securities		13,194		1,306		7,386		1,114		20,580		2,420
	$	2,475,872	$	173,301	$	3,007,890	$	583,187	$	5,483,762	$	756,488

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	$	11,637	$	11,573
Due after one year through five years		538,020		520,589
Due after five years through ten years		918,433		851,024
Due after ten years		1,356,974		1,240,574
Total held to maturity securities	$	2,825,064	$	2,623,760

Securities with Unrealized Losses

Held to maturity
March 31, 2023	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	$	49,176	$	2,085	$	305,813	$	39,453	$	354,989	$	41,538
Municipal obligations		240,561		1,452		183,368		17,810		423,929		19,262
Residential mortgage-backed securities		225,019		9,134		426,955		54,392		651,974		63,526
Commercial mortgage-backed securities		159,220		6,140		707,420		71,513		866,640		77,653
Collateralized mortgage obligations		2,662		30		36,360		2,106		39,022		2,136
	$	676,638	$	18,841	$	1,659,916	$	185,274	$	2,336,554	$	204,115

Held to maturity
December 31, 2022	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	$	145,893	$	13,245	$	226,499	$	35,799	$	372,392	$	49,044
Municipal obligations		560,288		8,878		64,346		17,680		624,634		26,558
Residential mortgage-backed securities		391,146		30,515		270,800		42,017		661,946		72,532
Commercial mortgage-backed securities		697,827		56,899		163,653		30,312		861,480		87,211
Collateralized mortgage obligations		41,438		2,526		—		—		41,438		2,526
	$	1,836,592	$	112,063	$	725,298	$	125,808	$	2,561,890	$	237,871