Pension plans and other postretirement benefits

6 Months Ended

Jun. 30, 2011

Pension plans and other postretirement benefits [Abstract]

Pension plans and other postretirement benefits

7. Pension plans and other postretirement benefits

The Company provides defined benefit pension and other postretirement benefits (including health care and life insurance benefits) to qualified retired employees. Net periodic defined benefit cost for defined benefit plans consisted of the following:

							Other
	Pension						postretirement
	benefits						benefits
	Three months ended June 30
	2011			2010			2011		2010
				(in thousands)
Service cost	$	6,413			4,960			115		102
Interest cost on projected benefit obligation		14,086			12,032			909		785
Expected return on plan assets		(14,563	)		(12,655	)		—		—
Amortization of prior service cost		(1,629	)		(1,629	)		29		63
Amortization of net actuarial loss		5,165			3,455			18		(5	)
Net periodic benefit cost	$	9,472			6,163			1,071		945

							Other
	Pension						postretirement
	benefits						benefits
				Six months ended June 30
	2011			2010			2011		2010
				(in thousands)
Service cost	$	11,713			9,835			240		202
Interest cost on projected benefit obligation		26,236			24,061			1,684		1,565
Expected return on plan assets		(27,263	)		(25,443	)		—		—
Amortization of prior service cost		(3,279	)		(3,279	)		54		88
Amortization of net actuarial loss		10,265			6,776			18		(5	)
Net periodic benefit cost	$	17,672			11,950			1,996		1,850

     Expense incurred in connection with the Company’s defined contribution pension and retirement savings plans totaled $9,890,000 and $8,775,000 for the three months ended June 30, 2011 and 2010, respectively, and $20,066,000 and $20,465,000 for the six months ended June 30, 2011 and 2010, respectively.