Employee benefit plans

6 Months Ended

Jun. 30, 2012

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 June 30,	2012			2011			2012			2011
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	350		$	827		$	461		$	383
Interest cost	4,262			4,959			1,038			1,161
Expected return on assets	(5,845		)	(5,727		)	(1,201		)	(1,308		)
Amortization of prior service cost (credit)	(21		)	44			(272		)	(669		)
Amortization of net actuarial (gain) loss	2,102			1,049			887			(53		)
Amortization of net transition obligation	—			—			531			531
Curtailment loss	—			1,218			—			—
Net periodic benefit cost, including amount capitalized	848			2,370			1,444			45
Less amount capitalized	196			287			183			(28		)
Net periodic benefit cost	$	652		$	2,083		$	1,261		$	73
							Other
							Postretirement
	Pension Benefits						Benefits
Six Months Ended June 30,	2012			2011			2012			2011
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	695		$	1,654		$	873		$	722
Interest cost	8,816			9,919			2,181			2,350
Expected return on assets	(11,731		)	(11,427		)	(2,445		)	(2,526		)
Amortization of prior service cost (credit)	(42		)	87			(544		)	(1,338		)
Amortization of net actuarial loss	3,783			2,592			1,413			258
Amortization of net transition obligation	—			—			1,063			1,062
Curtailment loss	—			1,218			—			—
Net periodic benefit cost, including amount capitalized	1,521			4,043			2,541			528
Less amount capitalized	430			535			321			(95		)
Net periodic benefit cost	$	1,091		$	3,508		$	2,220		$	623

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, all benefit and service accruals for an additional union plan 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 an unfunded, nonqualified benefit plan for executive officers and certain key management employees that generally provides 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 and six months ended June 30, 2012, was $2.0 million and $4.1 million, respectively. The Company's net periodic benefit cost for this plan for the three and six months ended June 30, 2011, was $1.9 million and $4.0 million, respectively.