Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance (in shares) at Aug. 31, 2019		51,776				20,262
Beginning balance at Aug. 31, 2019	$ 632,212	$ 25,888	$ 91,185	$ 866,886	$ (491)	$ (351,256)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures	3,641		3,624			17
Issuance of stock, net	618		(2,031)			$ 2,649
Issuance of stock, net (in shares)						153
Issuance of stock for acquisition	92,572		57,811			$ 34,761
Issuance of stock for acquisition (in shares)						2,000
Repurchase of common stock (in shares)						(44)
Repurchase of common stock	(1,737)					$ (1,737)
Common stock dividends	(7,228)			(7,228)
Amortization of net actuarial loss (net of tax of $3, $3, $6, and $5)	16				16
Interest rate swap activity, net of tax	(68)				(68)
Equity component of convertible senior notes and offering costs, net of tax of $20,840	61,335		61,335
Convertible note hedge purchase, net of tax of $17,417	(53,383)		(53,383)
Warrant transactions	42,210		42,210
Net income	31,336			31,336
Ending balance (in shares) at Feb. 29, 2020		51,776				18,153
Ending balance at Feb. 29, 2020	801,524	$ 25,888	200,751	890,994	(543)	$ (315,566)
Beginning balance (in shares) at Nov. 30, 2019		51,776				18,177
Beginning balance at Nov. 30, 2019	785,609	$ 25,888	198,733	877,469	(551)	$ (315,930)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures	1,838		1,830			$ 8
Stock-based compensation, net of forfeitures (in shares)						0
Issuance of stock, net	618		188			$ 430
Issuance of stock, net (in shares)						25
Repurchase of common stock (in shares)						(1)
Repurchase of common stock	(74)					$ (74)
Common stock dividends	(3,743)			(3,743)
Amortization of net actuarial loss (net of tax of $3, $3, $6, and $5)	8				8
Net income	17,268			17,268
Ending balance (in shares) at Feb. 29, 2020		51,776				18,153
Ending balance at Feb. 29, 2020	801,524	$ 25,888	200,751	890,994	(543)	$ (315,566)
Beginning balance (in shares) at Aug. 29, 2020		51,776				18,133
Beginning balance at Aug. 29, 2020	827,466	$ 25,888	203,791	913,610	(526)	$ (315,297)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures	6,981		6,968			$ 13
Stock-based compensation, net of forfeitures (in shares)						1
Issuance of stock, net	1,599		(1,032)			$ 2,631
Issuance of stock, net (in shares)						149
Repurchase of common stock (in shares)						(242)
Repurchase of common stock	(12,109)					$ (12,109)
Common stock dividends	(8,081)			(8,081)
Amortization of net actuarial loss (net of tax of $3, $3, $6, and $5)	17				17
Net income	126,491			126,491
Ending balance (in shares) at Feb. 27, 2021		51,776				18,225
Ending balance at Feb. 27, 2021	942,364	$ 25,888	209,727	1,032,020	(509)	$ (324,762)
Beginning balance (in shares) at Nov. 28, 2020		51,776				18,275
Beginning balance at Nov. 28, 2020	871,558	$ 25,888	204,551	966,945	(517)	$ (325,309)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures	4,627		4,622			$ 5
Stock-based compensation, net of forfeitures (in shares)						1
Issuance of stock, net	1,599		554			$ 1,045
Issuance of stock, net (in shares)						58
Repurchase of common stock (in shares)						(9)
Repurchase of common stock	(503)					$ (503)
Common stock dividends	(3,993)			(3,993)
Amortization of net actuarial loss (net of tax of $3, $3, $6, and $5)	8				8
Net income	69,068			69,068
Ending balance (in shares) at Feb. 27, 2021		51,776				18,225
Ending balance at Feb. 27, 2021	$ 942,364	$ 25,888	$ 209,727	$ 1,032,020	$ (509)	$ (324,762)