Employee Benefit Plans (Defined Benefit Pension Plans not Recognized as Component of Combined Net Period Benefit Cost) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Amounts included in accumulated other comprehensive loss, net of tax	$ 22,644	$ (22,940)	$ 6,113
Not Recognized As Combined Net Period Benefit Cost [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	(75,038)	(40,201)
Deferred tax benefit	26,263	14,070
Amounts included in accumulated other comprehensive loss, net of tax	$ (48,775)	$ (26,131)