Quarterly report pursuant to Section 13 or 15(d)

Parent, Guarantor, Non-Guarantor Unaudited Consolidating Condensed Financial Statements - Additional Information (Detail)

v2.4.0.6
Parent, Guarantor, Non-Guarantor Unaudited Consolidating Condensed Financial Statements - Additional Information (Detail)
 12 Months Ended
Dec. 31, 2012
Mar. 31, 2013
9.125% Senior Notes, due April 2018 [Member]
Dec. 31, 2012
9.125% Senior Notes, due April 2018 [Member]
Supplemental Guarantor Financial Information [Line Items]      
Percentage of notes guaranteed by restricted subsidiaries   9.125% 9.125%
Percentage of guaranteed subsidiaries by the parent companies 100.00%