Employee Benefits

Retirement Plans

The net periodic benefit cost recognized for the three, nine and twelve months ended September 30, 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						Nine Months Ended						Twelve Months Ended
	September 30,						September 30,						September 30,
	2013			2012			2013			2012			2013			2012
Components of net periodic benefit cost:
Service cost	$	2,166		$	2,207		$	6,996		$	6,621		$	9,204		$	8,334
Interest cost	3,410			3,389			10,210			10,167			13,600			13,663
Expected return on plan assets	(4,281		)	(3,611		)	(12,831		)	(10,832		)	(16,442		)	(14,356		)
Amortization of:
Net loss	2,903			2,839			8,323			8,517			11,162			10,153
Prior service cost	23			29			73			87			101			115
Net periodic benefit cost	$	4,221		$	4,853		$	12,771		$	14,560		$	17,625		$	17,909

During the nine months ended September 30, 2013, the Company contributed $16.4 million of its projected $16.8 million 2013 annual contribution to its retirement plans.

Other Postretirement Benefits

The net periodic benefit cost recognized for the three, nine and twelve months ended September 30, 2013 and 2012 is made up of the components listed below (in thousands):



	Three Months Ended						Nine Months Ended						Twelve Months Ended
	September 30,						September 30,						September 30,
	2013			2012			2013			2012			2013			2012
Components of net periodic benefit cost:
Service cost	$	972		$	1,095		$	3,172		$	3,284		$	4,266		$	4,031
Interest cost	1,292			1,413			4,042			4,238			5,455			5,583
Expected return on plan assets	(485		)	(397		)	(1,435		)	(1,285		)	(1,864		)	(1,741		)
Amortization of:
Prior service benefit	(1,392		)	(1,470		)	(4,242		)	(4,408		)	(5,711		)	(5,890		)
Net loss	—			154			—			461			154			452
Net periodic benefit cost	$	387		$	795		$	1,537		$	2,290		$	2,300		$	2,435

During the nine months ended September 30, 2013, the Company contributed $3.1 million of its projected $3.1 million 2013 annual contribution to its other postretirement benefits plan.

On October 3, 2013, the Company's Compensation Committee of the Board of Directors approved an amendment to the Company's Other Postretirement Benefits Plan to limit the Company's exposure to increases in retiree medical costs associated with current and future retirees. In accordance with FASB guidance, the Company anticipates remeasuring the assets and liabilities of the plan during the fourth quarter of 2013.