INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2016

Investments, Debt and Equity Securities [Abstract]

Summary of available for sale and held to maturity investment securities

A summary of our investment securities portfolio as of December 31, 2016 and 2015 is as follows:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(Dollars in thousands)
December 31, 2016
Held-to-Maturity:
Mortgage-backed securities:
Residential-U.S. Government sponsored entities	$	124,082	$	92	$	(2,474	)	$	121,700
Commercial-U.S. Government sponsored entities	93,586		—		(920		)	92,666
Total	$	217,668	$	92	$	(3,394	)	$	214,366

Available-for-Sale:
Debt securities:
States and political subdivisions	$	184,836	$	2,002	$	(1,797	)	$	185,041
Corporate securities	98,596		974		(181		)	99,389
Mortgage-backed securities:
Residential-U.S. Government sponsored entities	775,803		3,698		(9,515		)	769,986
Residential-Non-government sponsored entities	51,681		627		(761		)	51,547
Commercial-Non-government sponsored entities	135,248		2,387		(411		)	137,224
Other	564		96		—			660
Total	$	1,246,728	$	9,784	$	(12,665	)	$	1,243,847



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(Dollars in thousands)
December 31, 2015
Held-to-Maturity:
Mortgage-backed securities:
Residential-U.S. Government sponsored entities	$	152,315	$	123	$	(2,915	)	$	149,523
Commercial-U.S. Government sponsored entities	95,602		—		(989		)	94,613
Total	$	247,917	$	123	$	(3,904	)	$	244,136

Available-for-Sale:
Debt securities:
States and political subdivisions	$	187,552	$	3,819	$	(898	)	$	190,473
Corporate securities	107,721		1,077		(227		)	108,571
Mortgage-backed securities:
Residential-U.S. Government sponsored entities	771,657		5,885		(5,633		)	771,909
Residential-Non-government sponsored entities	64,286		733		(987		)	64,032
Commercial-Non-government sponsored entities	135,439		2,033		(1,118		)	136,354
Other	848		68		—			916
Total	$	1,267,503	$	13,615	$	(8,863	)	$	1,272,255

Schedule of amortized cost and estimated fair value of investment securities by contractual maturity

The amortized cost and estimated fair value of our investment securities at December 31, 2016 by contractual maturity are shown below. Actual maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.



	December 31, 2016
	Amortized Cost		Estimated Fair Value
	(Dollars in thousands)
Held-to-Maturity:
Mortgage-backed securities	$	217,668	$	214,366

Available-for-Sale:
Due in one year or less	$	6,701	$	6,699
Due after one year through five years	132,559		133,374
Due after five years through ten years	67,541		67,664
Due after ten years	76,631		76,693
Mortgage-backed securities	962,732		958,757
Other	564		660
Total	$	1,246,728	$	1,243,847

Schedule of investment securities in an unrealized loss position

Provided below is a summary of investment securities which were in an unrealized loss position at December 31, 2016 and 2015:



	Less Than 12 Months					12 Months or Longer					Total
Description of Securities	Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses
	(Dollars in thousands)
December 31, 2016
Debt securities:
States and political subdivisions	$	85,288	$	(1,797	)	$	—	$	—		$	85,288	$	(1,797	)
Corporate securities	20,357		(181		)	—		—			20,357		(181		)

Mortgage-backed securities:
Residential-U.S. Government sponsored entities	648,923		(11,766		)	3,978		(223		)	652,901		(11,989		)
Residential-Non-government sponsored entities	30,596		(761		)	—		—			30,596		(761		)
Commercial-U.S. Government sponsored entities	92,666		(920		)	—		—			92,666		(920		)
Commercial-Non-government sponsored entities	52,880		(411		)	—		—			52,880		(411		)
Total temporarily impaired securities	$	930,710	$	(15,836	)	$	3,978	$	(223	)	$	934,688	$	(16,059	)



	Less Than 12 Months					12 Months or Longer					Total
Description of Securities	Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses			Estimated Fair Value		Unrealized Losses
	(Dollars in thousands)
December 31, 2015
Debt securities:
States and political subdivisions	$	30,481	$	(532	)	$	12,576	$	(366	)	$	43,057	$	(898	)
Corporate securities	32,977		(227		)	—		—			32,977		(227		)

Mortgage-backed securities:
Residential-U.S. Government sponsored entities	507,525		(6,241		)	88,271		(2,307		)	595,796		(8,548		)
Residential-Non-government sponsored entities	37,975		(987		)	—		—			37,975		(987		)
Commercial-U.S. Government sponsored entities	94,613		(989		)	—		—			94,613		(989		)
Commercial-Non-government sponsored entities	62,555		(961		)	4,644		(157		)	67,199		(1,118		)
Total temporarily impaired securities	$	766,126	$	(9,937	)	$	105,491	$	(2,830	)	$	871,617	$	(12,767	)