Investment Securities - (Tables)

6 Months Ended

Jun. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities

At June 30, 2016 and December 31, 2015, the Company held $1.0 billion and $1.2 billion of available-for-sale investment securities, respectively. Available-for-sale investment securities are summarized as follows as of the dates indicated:

	June 30, 2016
	Amortized		Gross		Gross
	cost		unrealized gains		unrealized losses		Fair value
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	265,667	$	8,575	$	—	$	274,242
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		765,669		4,235		(3,710)		766,194
Municipal securities		5,180		12		—		5,192
Other securities		419		—		—		419
Total	$	1,036,935	$	12,822	$	(3,710)	$	1,046,047

	December 31, 2015
	Amortized		Gross		Gross
	cost		unrealized gains		unrealized losses		Fair value
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	305,773	$	5,721	$	(516)	$	310,978
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		861,321		3,638		(19,416)		845,543
Municipal securities		306		—		—		306
Other securities		419		—		—		419
Total	$	1,167,819	$	9,359	$	(19,932)	$	1,157,246

Summary of unrealized losses for available-for-sale securities

The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period:

	June 30, 2016
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities (“MBS”):
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	15,714	$	(30)	$	461,067	$	(3,680)	$	476,781	$	(3,710)
Total	$	15,714	$	(30)	$	461,067	$	(3,680)	$	476,781	$	(3,710)

	December 31, 2015
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	value		losses		value		losses		value		losses
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	109,182	$	(516)	$	—	$	—	$	109,182	$	(516)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		67,527		(404)		575,954		(19,012)		643,481		(19,416)
Total	$	176,709	$	(920)	$	575,954	$	(19,012)	$	752,663	$	(19,932)

Held-to-maturity Securities

Held-to-maturity investment securities are summarized as follows as of the dates indicated:

	June 30, 2016
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	302,852	$	6,746	$	—	$	309,598
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		78,320		506		(319)		78,507
Total investment securities held-to-maturity	$	381,172	$	7,252	$	(319)	$	388,105

	December 31, 2015
			Gross		Gross
	Amortized		unrealized		unrealized
	cost		gains		losses		Fair value
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	340,131	$	2,911	$	(230)	$	342,812
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		87,372		35		(1,634)		85,773
Total investment securities held-to-maturity	$	427,503	$	2,946	$	(1,864)	$	428,585

Summary of unrealized losses for held-to-maturity securities

The table below summarizes the unrealized losses as of the dates shown, along with the length of the impairment period:

	June 30, 2016
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
Mortgage-backed securities (“MBS”):
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	—	$	—	$	36,935	$	(319)	$	36,935	$	(319)
Total	$	—	$	—	$	36,935	$	(319)	$	36,935	$	(319)

	December 31, 2015
	Less than 12 months				12 months or more				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
	Value		Losses		Value		Losses		Value		Losses
Mortgage-backed securities (“MBS”):
Residential mortgage pass-through securities issued or guaranteed by U.S. Government agencies or sponsored enterprises	$	34,641	$	(205)	$	853	$	(25)	$	35,494	$	(230)
Other residential MBS issued or guaranteed by U.S. Government agencies or sponsored enterprises		28,490		(180)		45,872		(1,454)		74,362		(1,634)
Total	$	63,131	$	(385)	$	46,725	$	(1,479)	$	109,856	$	(1,864)