Employee Benefit Plans (Tables)

9 Months Ended

Oct. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Periodic Pension and Other Postretirement Benefit Expense

Net periodic pension and other postretirement benefit expense included the following components:

	Three Months Ended October 31,
	Pension Benefits						Other Postretirement Benefits
(in thousands)	2013			2012			2013			2012
Net Periodic Benefit Cost:
Service cost	$	4,783		$	4,528		$	698		$	596
Interest cost	6,752			6,701			691			710
Expected return on plan assets	(5,560		)	(5,104		)	—			—
Amortization of prior service cost	243			254			(165		)	(165		)
Amortization of net loss	4,753			3,949			53			7
Net expense	$	10,971		$	10,328		$	1,277		$	1,148

	Nine Months Ended October 31,
	Pension Benefits						Other Postretirement Benefits
(in thousands)	2013			2012			2013			2012
Net Periodic Benefit Cost:
Service cost	$	14,360		$	13,566		$	2,094		$	1,787
Interest cost	20,256			20,099			2,072			2,130
Expected return on plan assets	(16,680		)	(15,312		)	—			—
Amortization of prior service cost	729			762			(495		)	(495		)
Amortization of net loss	14,258			11,927			159			22
Net expense	$	32,923		$	31,042		$	3,830		$	3,444