Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Components of Net Periodic Benefit Income for the Pension Plans

Net periodic benefit income for the pension plans included the following components for the three months ended March 31:

	Pension Benefits
	2016			2015
	(in thousands)
Service cost	$	2,027		$	2,387
Interest cost		26,091			24,612
Expected return on plan assets		(39,138	)		(37,647	)
Amortization of prior service credit		(108	)		(141	)
Amortization of actuarial loss		7,795			9,613
Net periodic benefit income	$	(3,333	)	$	(1,176	)