Components of Long-Term Debt (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2012 Term loan facility, at a rate of 2.75%, due 10/1/2014	Dec. 31, 2012 3.875% Convertible Senior Subordinated Notes Due 2017	Dec. 31, 2011 3.875% Convertible Senior Subordinated Notes Due 2017	Dec. 31, 2012 6.875% Senior Subordinated Notes Due 2019	Jun. 13, 2012 6.875% Senior Subordinated Notes Due 2019
Line of Credit Facility [Line Items]
Interest rate	2.75%
Debt maturity date	Oct. 01, 2014
Interest rate		3.875%	3.875%	6.875%	6.875%
Debt instrument maturity date		2017	2017	2019	2019