Pension Plans and Defined Contribution Plan - Schedule of Actuarial Assumptions for Discount Rates, Expected Long-Term Rates of Return on Plan Assets, and Rates of Increase in Compensation and Healthcare Costs (Detail) (Pension Plans [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Assumed discount rate, general	4.95%	4.30%	5.00%
Assumed discount rate, union	5.10%	4.45%	5.00%
General Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets	7.30%	7.75%	7.75%
Union Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return on plan assets	7.75%	7.75%	7.75%