Derivative Financial Instruments and Hedging Activities Gains (Losses) Included in Other Comprehensive Income on Derivatives Accounted for as Hedging Instruments, Net of Tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Interest rate derivatives	$ 0	$ (3,252)	$ 0	$ (10,070)