Carrying Values of Long-Term Debt and Other Borrowing Arrangements (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Debt Instrument [Line Items]
Total senior subordinated notes	959,762	550,926
Term Loan	255,400
Total debt and other borrowing arrangements	972,532	550,926
Less current maturities of Term Loan	(12,770)
Long-term debt	959,762	550,926
5.5% Senior subordinated notes due 2022
Debt Instrument [Line Items]
Total debt and other borrowing arrangements	700,000
9.25% Senior subordinated notes due 2019
Debt Instrument [Line Items]
Total debt and other borrowing arrangements	17,132	200,926
7.0% Senior subordinated notes due 2017
Debt Instrument [Line Items]
Total debt and other borrowing arrangements		350,000
Revolving Credit Agreement
Debt Instrument [Line Items]
Revolving credit agreement	-	-
Senior Secured Facility
Debt Instrument [Line Items]
Total debt and other borrowing arrangements	255,400