Long-Term Debt - Additional information (Detail) (USD $)	3 Months Ended								6 Months Ended	9 Months Ended					3 Months Ended		1 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Including Acquisition Bridge Debt	Mar. 31, 2013 Excluding Acquisition Bridge Debt	Mar. 31, 2013 Unrestricted Cash Reduction Minimum	Mar. 31, 2013 Unrestricted Cash Reduction Maximum	Mar. 31, 2013 6.6% Senior Notes, Due 2018	Mar. 31, 2013 After Amendment	Jun. 30, 2013 After Amendment	Sep. 30, 2013 Before Amendment	Mar. 31, 2013 Term Loan Facility	Mar. 31, 2013 Revolving Facility	Dec. 31, 2012 Revolving Facility	Mar. 31, 2012 Revolving Facility	Mar. 31, 2013 AR Credit Facility	Mar. 31, 2013 AR Credit Facility Issuance of Debt	Apr. 30, 2013 Trade Receivable Credit Facility Issuance of Debt	Apr. 19, 2013 Trade Receivable Credit Facility Issuance of Debt	Apr. 30, 2013 Trade Receivable Credit Facility Issuance of Debt London Interest Bank Offer Rate	Apr. 30, 2013 Trade Receivable Credit Facility Issuance of Debt Minimum
Debt Instrument
Credit facility commitment											$ 250,000,000	$ 350,000,000
Credit facility, additional commitment amount															100,000,000
Debt covenant			3.50x	3.75x				3.75	3.75	3.50
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	2,507,000	2,507,000
Additional interest expense	269,000	251,000
Increase in annual interest expense due to ongoing amortization of the terminated value of the swap agreements							1,000,000
Debt instrument maturity period																2013-04-19
Trade receivable securitization facility																		150,000,000
Credit facility, interest above one month LIBOR rate																			0.60%
Credit facility, additional commitment amount																	$ 100,000,000			$ 25,000,000
Credit facility, maturity date																	Apr. 19, 2014