Employee Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (Pension Benefits [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 19,083,000	$ 15,254,000	$ 13,039,000
Interest cost	89,408,000	100,338,000	97,293,000
Expected return on plan assets	(133,816,000)	(128,208,000)	(124,150,000)
Amortization of prior service credit	(7,538,000)	(7,270,000)	(6,970,000)
Amortization of actuarial loss	83,934,000	70,161,000	53,039,000
Curtailment gain		(23,507,000)
Net periodic benefit cost	$ 51,071,000	$ 26,768,000	$ 32,251,000