Note 18 - Debt (Details Textual) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Mar. 17, 2017	May 31, 2019	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017	Mar. 31, 2019	Mar. 29, 2019
Long-term Debt, Total			$ 574,174	$ 574,775
Interest Expense, Debt, Total			$ 19,800	$ 15,900	$ 8,400
Weighted Average [Member]
Line of Credit Facility, Interest Rate at Period End			3.35%	2.69%
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate			0.875%
The 2019 Revolving Credit Facility [Member] | PNC Bank, National Associations [Member]
Line of Credit Facility, Maximum Borrowing Capacity							$ 750,000
Line of Credit Facility, Maximum Amount Of Additional Borrowings			$ 175,000				500,000
Line of Credit Facility, Minimum Borrowing Amount Required for Additional Borrowings							25,000
Long-term Line of Credit, Total			$ 575,000
Line of Credit Facility, Commitment Fee Percentage		0.10%
Debt Issuance Costs, Net, Total						$ 900
Long-term Debt, Gross							$ 575,000
The 2019 Revolving Credit Facility [Member] | PNC Bank, National Associations [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate			0.875%
The 2017 Revolving Credit Facility [Member] | PNC Bank, National Associations [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 575,000
Line of Credit Facility, Maximum Amount Of Additional Borrowings	225,000
Line of Credit Facility, Minimum Borrowing Amount Required for Additional Borrowings	$ 25,000
Long-term Debt, Total			$ 575,000
The 2017 Revolving Credit Facility [Member] | PNC Bank, National Associations [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	1.00%