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:


	Pension benefits						Other postretirement benefits
	Three months ended September 30
	2013			2012			2013			2012
	(in thousands)

Service cost	$	6,090			7,387			186			167
Interest cost on projected benefit obligation		15,032			15,509			673			934
Expected return on plan assets		(21,838	)		(17,627	)		—			—
Amortization of prior service cost		(1,639	)		(1,640	)		(340	)		5
Amortization of net actuarial loss		10,269			9,291			90			133


Net periodic benefit cost	$	7,914			12,920			609			1,239


	Pension benefits						Other postretirement benefits
	Nine months ended September 30
	2013			2012			2013			2012
	(in thousands)

Service cost	$	18,270			22,162			557			501
Interest cost on projected benefit obligation		45,097			46,527			2,018			2,803
Expected return on plan assets		(65,515	)		(52,883	)		—			—
Amortization of prior service cost		(4,917	)		(4,919	)		(1,019	)		15
Amortization of net actuarial loss		30,807			27,874			270			398


Net periodic benefit cost	$	23,742			38,761			1,826			3,717

Expense incurred in connection with the Company’s defined contribution pension and retirement savings plans totaled $12,440,000 and $11,289,000 for the three months ended September 30, 2013 and 2012, respectively, and $40,757,000 and $37,304,000 for the nine months ended September 30, 2013 and 2012, respectively.