Income Taxes - Provision for (Benefit from) Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2017	May 31, 2017	Feb. 28, 2017	Nov. 30, 2016	Feb. 28, 2018	Feb. 28, 2017	May 31, 2018	May 31, 2017	Aug. 31, 2018	Aug. 31, 2017	Aug. 31, 2016
Current:
Federal													$ 15,576	$ 8,394	$ (14,536)
State													7,041	(1,787)	2,427
Foreign													20,268	6,736	3,018
Current Total													42,885	13,343	(9,091)
Deferred:
Federal													(146,780)	(173,184)	34,753
State													(127)	(13,244)	(13,684)
Foreign													(54)	(8,039)	7,121
Deferred Total													(146,961)	(194,467)	28,190
Total	$ 7,787	$ 55,219	$ (187,688)	$ 20,606	$ (34,761)	$ (166,124)	$ 3,685	$ 16,076	$ (167,082)	$ 19,761	$ (111,863)	$ (146,363)	$ (104,076)	$ (181,124)	$ 19,099