Employee benefit plans (Tables)

3 Months Ended

Mar. 31, 2012

Employee Benefit Plans [Abstract]

Schedule of net benefit costs

Components of net periodic benefit cost for the Company's pension and other postretirement benefit plans were as follows:

Three Months Ended March 31,	Pension Benefits						Other Postretirement Benefits
	2012			2011			2012			2011
	(In thousands)
Components of net periodic benefit cost:
Service cost	$	345		$	827		$	412		$	339
Interest cost	4,554			4,960			1,143			1,189
Expected return on assets	(5,886		)	(5,700		)	(1,244		)	(1,218		)
Amortization of prior service cost (credit)	(21		)	43			(272		)	(669		)
Amortization of net actuarial loss	1,681			1,543			526			311
Amortization of net transition obligation	—			—			532			531
Net periodic benefit cost, including amount capitalized	673			1,673			1,097			483
Less amount capitalized	234			248			138			(67		)
Net periodic benefit cost	$	439		$	1,425		$	959		$	550