Securities (Tables)

3 Months Ended

Mar. 31, 2021

Investments, Debt and Equity Securities [Abstract]

The book values and approximate fair values of investment securities at March 31, 2021 and December 31, 2020 are summarized as follows:


($ in thousands)	March 31, 2021					December 31, 2020
	Amortized Cost		Fair Value	Unrealized		Amortized Cost	Fair Value	Unrealized
				Gains	(Losses)			Gains	(Losses)
Securities available for sale:
Government-sponsored enterprise securities	$	70,015	67,022	—	(2,993)	70,016	70,206	371	(181)
Mortgage-backed securities	1,711,809		1,709,811	17,167	(19,165)	1,318,998	1,337,706	20,832	(2,124)
Corporate bonds	43,660		44,864	1,414	(210)	43,670	45,220	1,760	(210)
Total available for sale	$	1,825,484	1,821,697	18,581	(22,368)	1,432,684	1,453,132	22,963	(2,515)

Securities held to maturity:
Mortgage-backed securities	$	26,977	27,999	1,022	—	29,959	30,900	941	—
State and local governments	171,866		167,425	410	(4,851)	137,592	139,834	2,407	(165)
Total held to maturity	$	198,843	195,424	1,432	(4,851)	167,551	170,734	3,348	(165)

Schedule of unrealized losses on investment securities

The following table presents information regarding securities with unrealized losses at March 31, 2021:


($ in thousands)	Securities in an Unrealized Loss Position for Less than 12 Months			Securities in an Unrealized Loss Position for More than 12 Months		Total
	Fair Value		Unrealized Losses	Fair Value	Unrealized Losses	Fair Value	Unrealized Losses
Government-sponsored enterprise securities	$	67,022	2,993	—	—	67,022	2,993
Mortgage-backed securities	1,094,263		19,010	5,844	155	1,100,107	19,165
Corporate bonds	—		—	4,790	210	4,790	210
State and local governments	108,006		4,851	—	—	108,006	4,851
Total unrealized loss position	$	1,269,291	26,854	10,634	365	1,279,925	27,219

The following table presents information regarding securities with unrealized losses at December 31, 2020:


($ in thousands)	Securities in an Unrealized Loss Position for Less than 12 Months			Securities in an Unrealized Loss Position for More than 12 Months		Total
	Fair Value		Unrealized Losses	Fair Value	Unrealized Losses	Fair Value	Unrealized Losses
Government-sponsored enterprise securities	$	29,812	181	—	—	29,812	181
Mortgage-backed securities	497,992		1,957	6,168	167	504,160	2,124
Corporate bonds	3,956		45	835	165	4,791	210
State and local governments	23,310		165	—	—	23,310	165
Total unrealized loss position	$	555,070	2,348	7,003	332	562,073	2,680

Schedule of contractual maturity of investment securities

The book values and approximate fair values of investment securities at March 31, 2021, by contractual maturity, are summarized in the table below. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.


	Securities Available for Sale			Securities Held to Maturity
($ in thousands)	Amortized Cost		Fair Value	Amortized Cost	Fair Value
Securities
Due within one year	$	—	—	1,587	1,620
Due after one year but within five years	28,660		30,023	537	557
Due after five years but within ten years	74,015		71,578	5,355	5,389
Due after ten years	11,000		10,285	164,387	159,859
Mortgage-backed securities	1,711,809		1,709,811	26,977	27,999
Total securities	$	1,825,484	1,821,697	198,843	195,424