Long-Term Debt (Detail) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2011
Debt Instrument [Line Items]
Total Debt	587,561,000	$ 602,560,000
Current portion, long-term debt	22,500,000	15,000,000
Long-term debt	565,061,000	587,560,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	37,500,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	45,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	222,500,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Long-term Debt, Maturities, Repayments of Principal after Year Five	260,100,000
Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Total Debt	50,000,000	50,000,000
Senior Secured Term Loan A
Debt Instrument [Line Items]
Total Debt	277,500,000	292,500,000
Senior Secured Convertible Notes due 2033 Member
Debt Instrument [Line Items]
Total Debt	61,000	60,000
Senior Notes due 2021
Debt Instrument [Line Items]
Total Debt		$ 260,000,000	$ 260,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.625%	6.625%