Notes Payable and Long-Term Debt (Details)	1 Months Ended	2 Months Ended	12 Months Ended
	Nov. 30, 2014 USD ($)	May. 31, 2016 USD ($)	Mar. 31, 2016 USD ($)
Notes Payable and Long-Term Debt
Maximum borrowing capacity with contingent increase			$ 600,000,000
Credit Agreement
Notes Payable and Long-Term Debt
Term of agreement (in years)	5 years
Current borrowing capacity	$ 400,000,000
Maximum available for the issuance of letters of credit	75,000,000
Maximum available for swing loans	$ 5,000,000
Additional available credit			200,000,000
Capacity available for currency borrowings			$ 150,000,000
Period of variable interest rate basis (in days)			30 days
Spread on variable interest rate (as a percent)			1.00%
Fees on the daily unused amount (as a percent)			0.175%
Additional Financial Covenants Required
Total adjusted leverage ratio, numerator, to allow for maximum limit on acquisitions under terms of the Credit Agreement covenants			2.75
Credit Agreement | Minimum
Notes Payable and Long-Term Debt
Fees on the daily unused amount (as a percent)			0.175%
Additional Financial Covenants Required
Asset coverage ratio, numerator, to be maintained under Credit Agreement covenants			3.25
Ratio of consolidated EBITDA plus annual rental expense to annual interest expense plus annual rental expense, numerator, to be maintained under Credit Agreement covenants			2.25
Credit Agreement | Maximum
Notes Payable and Long-Term Debt
Fees on the daily unused amount (as a percent)			0.30%
Additional Financial Covenants Required
Debt Instrument, Covenant Capital Expenditures Allowed			$ 110,000,000
Total adjusted leverage ratio, numerator, to allow for maximum limit on acquisitions under terms of the Credit Agreement covenants			2.75
Additional unsecured debt allowed under Credit Agreement covenants			$ 200,000,000
Credit Agreement | LIBOR based interest rates
Notes Payable and Long-Term Debt
Adjusted LIBOR rate at period end (as a percent)			0.44%
Credit Agreement | LIBOR based interest rates | First 30 days
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)			1.25%
Credit Agreement | LIBOR based interest rates | Thereafter
Notes Payable and Long-Term Debt
Variable interest rate basis			LIBOR
Credit Agreement | LIBOR based interest rates | Thereafter | Minimum
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)			1.25%
Credit Agreement | LIBOR based interest rates | Thereafter | Maximum
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)			2.00%
Credit Agreement | Alternate Base Rate based interest rates | First 30 days
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)			0.25%
Credit Agreement | Alternate Base Rate based interest rates | Thereafter
Notes Payable and Long-Term Debt
Spread on variable interest rate (as a percent)			0.25%
Line of Credit | Second Amended And Restated Credit Agreement, As Amended | Subsequent Event
Additional Financial Covenants Required
Long-term Line of Credit		$ 113,000,000
Line of Credit | Revolving Credit Facility
Additional Financial Covenants Required
Deferred financing costs			$ 1,300,000
Line of Credit | Revolving Credit Facility | Second Amended And Restated Credit Agreement, As Amended
Notes Payable and Long-Term Debt
Current borrowing capacity			53,000,000
Additional Financial Covenants Required
Proceeds from Lines of Credit			426,000,000
Repayments of Lines of Credit			373,000,000
Outstanding letters of credit			700,000
Amount available under the Credit Agreement			$ 346,300,000
Line of Credit | Revolving Credit Facility | Second Amended And Restated Credit Agreement, As Amended | Subsequent Event
Additional Financial Covenants Required
Repayments of Lines of Credit		16,000,000
Long-term Line of Credit		$ 76,000,000