Retirement Plans and Other Post-Retirement Benefits - Benefit Payments Expected under Non-Qualified Pension Plans and Other Benefit Plans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Nonqualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit payments expected	$ 2,257
Other Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit payments expected	$ 4,032