Employee Benefits

3 Months Ended

Mar. 31, 2013

General Discussion of Pension and Other Postretirement Benefits [Abstract]

Employee Benefits

Employee Benefits

Retirement Plans

The net periodic benefit cost recognized for the three and twelve months endedMarch 31, 2013 and 2012 is made up of the components listed below as determined using the projected unit credit actuarial cost method (in thousands):

	Three Months Ended						Twelve Months Ended
	March 31,						March 31,
	2013			2012			2013			2012
Components of net periodic benefit cost:
Service cost	$	2,400		$	2,225		$	9,004		$	7,332
Interest cost	3,400			3,378			13,579			13,870
Expected return on plan assets	(4,275		)	(3,610		)	(15,108		)	(14,172		)
Amortization of:
Net loss	2,675			2,965			11,066			7,926
Prior service cost	25			27			113			115
Net periodic benefit cost	$	4,225		$	4,985		$	18,654		$	15,071

During the three months endedMarch 31, 2013, the Company contributed $15.5 million of its projected $21.8 million2013 annual contribution to its retirement plans.

Other Postretirement Benefits

The net periodic benefit cost recognized for the three and twelve months endedMarch 31, 2013 and 2012 is made up of the components listed below (in thousands):

	Three Months Ended						Twelve Months Ended
	March 31,						March 31,
	2013			2012			2013			2012
Components of net periodic benefit cost:
Service cost	$	1,100		$	1,070		$	4,408		$	3,320
Interest cost	1,375			1,415			5,611			5,504
Expected return on plan assets	(475		)	(435		)	(1,754		)	(1,800		)
Amortization of:
Prior service benefit	(1,425		)	(1,470		)	(5,832		)	(5,915		)
Net loss	—			160			455			229
Net periodic benefit cost	$	575		$	740		$	2,888		$	1,338

During the three months endedMarch 31, 2013, the Company contributed $2.0 million of its projected $4.0 million2013 annual contribution to its other postretirement benefits plan.