Earnings (Loss) Per Share - Reconciliation of Shares Used in Computation of Basic and Diluted Earnings (Loss) Per Common Share (Detail) - shares shares in Thousands		3 Months Ended		6 Months Ended
		Feb. 28, 2021	Feb. 29, 2020	Feb. 28, 2021	Feb. 29, 2020
Earnings Per Share Disclosure [Line Items]
Weighted average basic common shares outstanding	[1]	32,810	32,661	32,766	32,645
Dilutive effect of restricted stock units	[2],[3]		821		737
Weighted average diluted common shares outstanding		32,810	33,482	32,766	33,382
2.875% Convertible Senior Notes
Earnings Per Share Disclosure [Line Items]
Dilutive effect of convertible notes	[3],[4]	0	0	0	0
2.25% Convertible Senior Notes
Earnings Per Share Disclosure [Line Items]
Dilutive effect of convertible notes	[3],[5]	0	0	0	0

[1] Restricted stock grants and restricted stock units that are considered participating securities, including some grants subject to certain performance criteria, are included in weighted average basic common shares outstanding when the Company is in a net earnings position.

[2] Restricted stock units that are not considered participating securities and restricted stock units subject to performance criteria, for which actual levels of performance above target have been achieved, are included in weighted average diluted common shares outstanding when the Company is in a net earnings position.

[3] The dilutive effect of common stock equivalents was excluded from the share calculation for the three and six months ended February 28, 2021 due to a net loss.

[4] The dilutive effect of the 2.875% convertible notes was excluded for the three and six months ended February 29, 2020 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive.

[5] The dilutive effect of the 2.25% convertible notes was excluded for the three and six months ended February 29, 2020 as the average stock price was less than the applicable conversion price and therefore was considered anti-dilutive.