Investment Securities (Tables)

3 Months Ended

Dec. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Schedule of amortized cost, gross unrealized gains, gross unrealized losses and the fair value of securities available-for-sale

The following tables present the amortized cost, gross unrealized gains, gross unrealized losses and the fair value for securities available-for-sale at December 31, 2017 and September 30, 2017:

	December 31, 2017
	Amortized cost		Gross unrealized gains	Gross unrealized (losses)		Fair value
			(In thousands)
U.S. government and agency obligations	$	39,909	17	(282	)	$	39,644
Mortgage-backed securities and collateralized mortgage obligations	615,924		383	(9,695	)	606,612
Municipal obligations	1,957		—	—		1,957
Corporate debt securities	54,489		536	(511	)	54,514
Trust preferred securities	5,000		—	(344	)	4,656
Equity securities	2,328		859	—		3,187
	$	719,607	1,795	(10,832	)	$	710,570

	September 30, 2017
	Amortized cost		Gross unrealized gains	Gross unrealized (losses)		Fair value
			(In thousands)
U.S. government and agency obligations	$	24,954	35	(116	)	$	24,873
Mortgage-backed securities and collateralized mortgage obligations	479,927		652	(7,088	)	473,491
Municipal obligations	1,357		—			1,357
Corporate debt securities	49,489		536	(532	)	49,493
Trust preferred securities	5,000		—	(292	)	4,708
Equity securities	2,482		826	(54	)	3,254
	$	563,209	2,049	(8,082	)	$	557,176

Schedule of securities by contractual maturity

The table below presents the amortized cost and fair value of debt securities held-to-maturity at December 31, 2017 by contractual maturity. Expected maturities may differ from contractual maturities due to prepayment or early call privileges of the issuer.

	December 31, 2017
	Amortized cost		Fair value
	(In Thousands)
More than five years to ten years	$	8,402	$	8,344
	8,402		8,344
Mortgage-backed securities and collateralized mortgage obligations	231,216		227,781
	$	239,618	$	236,125

The table below presents the amortized cost and fair value of debt securities available-for-sale at December 31, 2017 by contractual maturity. Expected maturities may differ from contractual maturities due to prepayment or early call privileges of the issuer.

	December 31, 2017
	Amortized cost		Fair value
	(In thousands)
One year or less	$	1,957	$	1,957
More than one year to five years	34,954		34,934
More than five years to ten years	54,444		54,600
More than ten years	10,000		9,280
	$	101,355	$	100,771
Mortgage-backed securities and collateralized mortgage obligations	615,924		606,612
	$	717,279	$	707,383

Schedule of available-for-sale securities reported in a continuous unrealized loss position

The following tables summarize the fair value and gross unrealized losses of those securities that reported an unrealized loss at December 31, 2017 and September 30, 2017 and if the unrealized loss position was continuous for the twelve months prior to December 31, 2017 and September 30, 2017:

	December 31, 2017
	Less than 12 months				12 months or longer			Total
	Fair Value		Gross unrealized (losses)		Fair value	Gross unrealized (losses)		Fair value	Gross unrealized (losses)
	(In thousands)
U.S. government and agency obligations	$	29,654	(282	)	—	—		29,654	$	(282	)
Mortgage-backed securities and collateralized mortgage obligations	514,283		(8,037	)	48,788	(1,658	)	563,071	(9,695		)
Corporate debt securities	4,866		(135	)	4,624	(376	)	9,490	(511		)
Trust preferred securities	—		—		4,656	(344	)	4,656	(344		)
	$	548,803	(8,454	)	58,068	(2,378	)	606,871	$	(10,832	)
	September 30, 2017
	Less than 12 months				12 months or longer			Total
	Fair Value		Gross unrealized (losses)		Fair value	Gross unrealized (losses)		Fair value	Gross unrealized (losses)
	(In thousands)
U.S. government and agency obligations	$	14,831	(116	)	—	—		14,831	$	(116	)
Mortgage-backed securities and collateralized mortgage obligations	329,554		(5,346	)	49,695	(1,742	)	379,249	(7,088		)
Corporate debt securities	9,824		(176	)	9,644	(356	)	19,468	(532		)
Trust preferred securities	—		—		4,708	(292	)	4,708	(292		)
Equity securities	98		(54	)	—	—		98	(54		)
	$	354,307	(5,692	)	64,047	(2,390	)	418,354	$	(8,082	)

Schedule of amortized cost, gross unrealized gains, gross unrealized losses and the fair value of securities held-to-maturity

The following tables present the amortized cost, gross unrealized gains, gross unrealized losses and the fair value for securities held-to-maturity at December 31, 2017 and September 30, 2017:

	December 31, 2017
	Amortized cost		Gross unrealized gains	Gross unrealized (losses)		Fair value
	(In thousands)
U.S. government and agency obligations	$	8,402	—	(58	)	$	8,344
Mortgage-backed securities and collateralized mortgage obligations	231,216		—	(3,435	)	227,781
	$	239,618	—	(3,493	)	$	236,125
	September 30, 2017
	Amortized cost		Gross unrealized gains	Gross unrealized (losses)		Fair value
	(In thousands)
U.S. government and agency obligations	$	3,407	—	(7	)	$	3,400
Mortgage-backed securities and collateralized mortgage obligations	129,532		—	(1,110	)	128,422
	$	132,939	—	(1,117	)	$	131,822

Schedule of held-to-maturity securities reported in a continuous unrealized loss position

The following tables summarize the fair value and gross unrealized losses of those securities that reported an unrealized loss at December 31, 2017 and September 30, 2017 and if the unrealized loss position was continuous for the twelve months prior to December 31, 2017 and September 30, 2017:

	December 31, 2017
	Less than 12 months				12 months or longer			Total
	Fair Value		Gross unrealized (losses)		Fair value	Gross unrealized (losses)		Fair value	Gross unrealized (losses)
	(In thousands)
U.S. government and agency obligations	$	8,344	(58	)	—	—		8,344	$	(58	)
Mortgage-backed securities and collateralized mortgage obligations	196,049		(2,920	)	30,046	(515	)	226,095	(3,435		)
	$	204,393	(2,978	)	30,046	(515	)	234,439	$	(3,493	)
	September 30, 2017
	Less than 12 months				12 months or longer			Total
	Fair Value		Gross unrealized (losses)		Fair value	Gross unrealized (losses)		Fair value	Gross unrealized (losses)
	(In thousands)
U.S. government and agency obligations	$	—	—		3,400	(7	)	3,400	$	(7	)
Mortgage-backed securities and collateralized mortgage obligations	29,965		(349	)	96,076	(761	)	126,041	(1,110		)
	$	29,965	(349	)	99,476	(768	)	129,441	$	(1,117	)