Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Post-Retirement Benefit Costs

The following tables present a summary of post-retirement benefit costs by component.

Components of Post-Retirement Benefit Costs

	Three Months Ended June 30,
	Pension Benefits						Other Benefits
	2015			2014			2015		2014
Service cost	$	3,991		$	3,231		$	—	$	(7	)
Interest cost	5,004			4,819			204		150
Expected return on assets	(5,323		)	(4,752		)	—		—
Amortization:
Prior service cost	82			529			—		—
Actuarial (gain) loss	3,534			2,047			37		—
Direct recognition of expense	—			—			151		(42		)
Net periodic benefit cost	$	7,288		$	5,874		$	392	$	101
	Six Months Ended June 30,
	Pension Benefits						Other Benefits
	2015			2014			2015		2014
Service cost	$	7,981		$	6,463		$	—	$	49
Interest cost	10,006			9,638			407		297
Expected return on assets	(10,646		)	(9,505		)	—		—
Amortization:
Prior service cost	163			1,057			—		—
Actuarial (gain)/loss	7,068			4,092			60		—
Direct recognition of expense	—			—			327		(104		)
Net periodic benefit cost	$	14,572		$	11,745		$	794	$	242

Schedule of Defined-Benefit Plans Disclosures

The following chart presents assets at fair value for the defined-benefit pension plans at June 30, 2015 and the prior-year end.

Pension Assets by Component

	June 30, 2015			December 31, 2014
	Amount		%	Amount		%
Corporate debt	$	155,642	48	$	166,825	52
Other fixed maturities	277		—	284		—
Equity securities	127,530		40	127,568		39
Short-term investments	19,047		6	9,038		3
Guaranteed annuity contract	15,259		5	15,027		5
Other	3,063		1	4,156		1
Total	$	320,818	100	$	322,898	100