Employee benefit plans

3 Months Ended

Mar. 31, 2013

Employee Benefit Plans [Abstract]

Pension and Other Postretirement Benefits Disclosure

Employee benefit plans

The Company has noncontributory defined benefit pension plans and other postretirement benefit plans for certain eligible employees. Components of net periodic benefit cost for the Company's pension and other postretirement benefit plans were as follows:

							Other
							Postretirement
	Pension Benefits						Benefits
Three Months Ended March 31,	2013			2012			2013			2012
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	40		$	345		$	504		$	412
Interest cost	4,018			4,554			940			1,143
Expected return on assets	(5,083		)	(5,886		)	(1,107		)	(1,244		)
Amortization of prior service cost (credit)	18			(21		)	(364		)	(272		)
Amortization of net actuarial loss	1,864			1,681			671			526
Amortization of net transition obligation	—			—			—			532
Net periodic benefit cost, including amount capitalized	857			673			644			1,097
Less amount capitalized	110			234			29			138
Net periodic benefit cost	$	747		$	439		$	615		$	959

Defined pension plan benefits to all nonunion and certain union employees hired after December 31, 2005, were discontinued. Employees that would have been eligible for defined pension plan benefits are eligible to receive additional defined contribution plan benefits. Effective January 1, 2010, all benefit and service accruals for nonunion and certain union plans were frozen. Effective June 30, 2011 and September 30, 2012, all benefit and service accruals for certain additional union employees were frozen. These employees will be eligible to receive additional defined contribution plan benefits.

In addition to the qualified plan defined pension benefits reflected in the table, the Company has unfunded, nonqualified benefit plans for executive officers and certain key management employees that generally provide for defined benefit payments at age 65 following the employee's retirement or to their beneficiaries upon death for a 15-year period. The Company's net periodic benefit cost for this plan for the three months ended March 31, 2013 and 2012, was $1.9 million and $2.1 million, respectively.

In 2012, the Company modified health care coverage for certain retirees. Effective January 1, 2013, post-65 coverage is replaced by a fixed-dollar subsidy for retirees and spouses to be used to purchase individual insurance through an exchange.