Long-Term Debt - Additional information (Detail) (USD $)	3 Months Ended		9 Months Ended								9 Months Ended	1 Months Ended		1 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Including Acquisition Bridge Debt	Sep. 30, 2013 Excluding Acquisition Bridge Debt	Sep. 30, 2013 Unrestricted Cash Reduction Minimum	Sep. 30, 2013 Unrestricted Cash Reduction Maximum	Sep. 30, 2013 6.6% Senior Notes, Due 2018	Sep. 30, 2013 Revolving Facility	Sep. 30, 2013 AR Credit Facility	Apr. 30, 2013 Trade Receivable Credit Facility	Sep. 30, 2013 Trade Receivable Credit Facility	Apr. 30, 2013 Trade Receivable Credit Facility London Interbank Offered Rate(LIBOR)	Apr. 30, 2013 Trade Receivable Credit Facility Minimum	Sep. 30, 2013 Term Loan Facility
Debt Instrument
Credit facility commitment										$ 350,000,000	$ 100,000,000		$ 314,998,000			$ 250,000,000
Debt instrument maturity period											2013-04-20
Trade receivable securitization facility												150,000,000
Credit facility, LIBOR plus rate														0.60%
Credit facility, additional commitment amount												100,000,000			25,000,000
Credit facility, maturity date												Apr. 19, 2014
Debt covenant					3.50x	3.75x
Reduction of consolidated debt in the debt ratio calculation							50,000,000
Maximum consolidated debt reduction for unrestricted cash and cash equivalents for debt covenant calculation								200,000,000
Outstanding letters of credit										2,507,000
Additional interest expense	279,000	260,000	823,000	768,000
Increase in annual interest expense due to ongoing amortization of the terminated value of the swap agreements									$ 1,000,000