Offsetting Assets and Liabilities (Tables)

3 Months Ended

Mar. 31, 2013

Reverse Repurchase Agreements Securities Lending Transactions [Abstract]

Schedule of amounts outstanding under reverse repurchase agreements

				Gross
	Gross			Amounts					Gross Amounts not Offset
	Amounts of			Offset on the						in the Balance Sheet
	Recognized			Balance			Net Asset			Financial		Collateral
March 31, 2013	Assets			Sheet			Balance			Instruments		Received		Net Amount
Repurchase agreements / reverse repurchase agreements	$	332,000		$	(250,000	)	$	82,000		$	—	$	—	$	82,000
Derivatives		602			—			602			—		—		602
Total	$	332,602		$	(250,000	)	$	82,602		$	—	$	—	$	82,602
Weighted average interest rate of reverse repurchase agreements		1.28	%
				Gross
	Gross			Amounts						Gross Amounts not Offset
	Amounts of			Offset on the			Net			in the Balance Sheet
	Recognized			Balance			Liability			Financial		Collateral
	Liabilities			Sheet			Balance			Instruments		Pledged		Net Amount
Repurchase agreements / reverse repurchase agreements	$	250,000		$	(250,000	)	$	—		$	—	$	—	$	—
Derivatives		14,556			—			14,556			—		14,585		—
Total	$	264,556		$	(250,000	)	$	14,556		$	—	$	14,585	$	—
Weighted average interest rate of repurchase agreements		.37	%
				Gross
	Gross			Amounts						Gross Amounts not Offset
	Amounts of			Offset on the						in the Balance Sheet
	Recognized			Balance			Net Asset			Financial		Collateral
December 31, 2012	Assets			Sheet			Balance			Instruments		Received		Net Amount
Repurchase agreements / reverse repurchase agreements	$	325,000		$	(265,000	)	$	60,000		$	—	$	—	$	60,000
Securities lending transactions		50,000			(50,000	)		—			—		—		—
Derivatives		658			—			658			—		—		658
Total	$	375,658		$	(315,000	)	$	60,658		$	—	$	—	$	60,658
Weighted average interest rate of reverse repurchase agreements		1.18	%
				Gross
	Gross			Amounts						Gross Amounts not Offset
	Amounts of			Offset on the			Net			in the Balance Sheet
	Recognized			Balance			Liability			Financial		Collateral
	Liabilities			Sheet			Balance			Instruments		Pledged		Net Amount
Repurchase agreements / reverse repurchase agreements	$	265,000		$	(265,000	)	$	—		$	—	$	—	$	—
Securities lending transactions		50,000			(50,000	)		—			—		—		—
Derivatives		12,543			—			12,543			—		11,493		1,050
Total	$	327,543		$	(315,000	)	$	12,543		$	—	$	11,493	$	1,050
Weighted average interest rate of repurchase agreements		.43	%
				Gross
	Gross			Amounts						Gross Amounts not Offset
	Amounts of			Offset on the						in the Balance Sheet
	Recognized			Balance			Net Asset			Financial		Collateral
March 31, 2012	Assets			Sheet			Balance			Instruments		Received		Net Amount
Repurchase agreements / reverse repurchase agreements	$	406,000		$	(171,000	)	$	235,000		$	—	$	—	$	235,000
Derivatives		73			—			73			—		—		73
Total	$	406,073		$	(171,000	)	$	235,073		$	—	$	—	$	235,073
Weighted average interest rate of reverse repurchase agreements		1.17	%
				Gross
	Gross			Amounts						Gross Amounts not Offset
	Amounts of			Offset on the			Net			in the Balance Sheet
	Recognized			Balance			Liability			Financial		Collateral
	Liabilities			Sheet			Balance			Instruments		Pledged		Net Amount
Repurchase agreements / reverse repurchase agreements	$	171,000		$	(171,000	)	$	—		$	—	$	—	$	—
Derivatives		2,599			—			2,599			—		2,919		—
Total	$	173,599		$	(171,000	)	$	2,599		$	—	$	2,919	$	—
Weighted average interest rate of repurchase agreements		.32	%