Pension plans and other postretirement benefits

9 Months Ended

Sep. 30, 2015

Compensation and Retirement Disclosure [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:

	Pension benefits						Other postretirement benefits
	Three months ended September 30
	2015			2014			2015			2014
	(in thousands)
Service cost	$	5,916			5,130			188			151
Interest cost on projected benefit obligation		17,754			17,290			651			695
Expected return on plan assets		(23,527	)		(22,892	)		—			—
Amortization of prior service credit		(1,501	)		(1,638	)		(340	)		(340	)
Amortization of net actuarial loss		11,207			3,624			26			—
Net periodic benefit cost	$	9,849			1,514			525			506
	Pension benefits						Other postretirement benefits
	Nine months ended September 30
	2015			2014			2015			2014
	(in thousands)
Service cost	$	17,748			15,390			562			453
Interest cost on projected benefit obligation		53,261			51,871			1,953			2,084
Expected return on plan assets		(70,578	)		(68,676	)		—			—
Amortization of prior service credit		(4,504	)		(4,914	)		(1,019	)		(1,019	)
Amortization of net actuarial loss		33,619			10,871			79			—
Net periodic benefit cost	$	29,546			4,542			1,575			1,518

Expense incurred in connection with the Company’s defined contribution pension and retirement savings plans totaled $14,281,000 and $13,558,000 for the three months ended September 30, 2015 and 2014, respectively, and $44,377,000 and $41,963,000 for the nine months ended September 30, 2015 and 2014, respectively.