Employee Benefit Plans - Expected Cash Flows for Pension Plans (Detail) (Pension Benefits [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 50,605
Defined Benefit Plan, Expected Future Benefit Payments in Year One	79,073
Defined Benefit Plan, Expected Future Benefit Payments in Year Two	88,704
Defined Benefit Plan, Expected Future Benefit Payments in Year Three	96,385
Defined Benefit Plan, Expected Future Benefit Payments in Year Four	104,225
Defined Benefit Plan, Expected Future Benefit Payments in Year Five	112,082
Defined Benefit Plan, Expected Future Benefit Payments in Five Fiscal Years Thereafter	$ 662,040