- Summary of Long-Term Debt Obligations (Parenthetical) (Detail)	Dec. 31, 2013	Dec. 31, 2012
Revolver Borrowings due 2017
Debt Instrument [Line Items]
Average effective interest rate	2.70%	1.20%
Senior Term Loan due 2014 through 2017
Debt Instrument [Line Items]
Average effective interest rate	2.70%	3.00%
7 3/4% Senior Notes due 2018
Debt Instrument [Line Items]
Stated interest rate	7.75%	7.75%
6 7/8% Senior Notes due 2020
Debt Instrument [Line Items]
Stated interest rate	6.875%	6.875%
Debentures due 2013 through 2025
Debt Instrument [Line Items]
Average effective interest rate	7.50%	8.40%
Customer Notes due 2013
Debt Instrument [Line Items]
Average effective interest rate	8.00%	8.00%
Notes due 2013 through 2025
Debt Instrument [Line Items]
Average effective interest rate	1.30%	1.30%