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. 25, 2018		51,776				20,243
Beginning balance at Aug. 25, 2018	$ 534,445	$ 25,888	$ 86,223	$ 768,816	$ 892	$ (347,374)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures (in shares)						4
Stock-based compensation, net of forfeitures	5,752		5,683			$ 69
Issuance of stock, net (in shares)						208
Issuance of stock, net	1,528		(2,056)			$ 3,584
Issuance of stock under ESPP (in shares)						15
Issuance of stock under ESPP	296		46			$ 250
Repurchase of common stock (in shares)						(255)
Repurchase of common stock	(7,724)					$ (7,724)
Common stock dividends	(10,240)			(10,240)
Actuarial loss, net of tax	24				24
Interest rate swap activity, net of tax	(1,018)				(1,018)
Net income (loss)	79,930			79,930
Ending balance (in shares) at May. 25, 2019		51,776				20,271
Ending balance at May. 25, 2019	602,993	$ 25,888	89,896	838,506	(102)	$ (351,195)
Beginning balance (in shares) at Feb. 23, 2019		51,776				20,292
Beginning balance at Feb. 23, 2019	570,666	$ 25,888	89,682	805,851	252	$ (351,007)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures (in shares)						1
Stock-based compensation, net of forfeitures	1,130		1,118			$ 12
Issuance of stock, net (in shares)						52
Issuance of stock, net	0		(904)			$ 904
Repurchase of common stock (in shares)						(32)
Repurchase of common stock	(1,104)					$ (1,104)
Common stock dividends	(3,516)			(3,516)
Actuarial loss, net of tax	8				8
Interest rate swap activity, net of tax	(362)				(362)
Net income (loss)	36,171			36,171
Ending balance (in shares) at May. 25, 2019		51,776				20,271
Ending balance at May. 25, 2019	602,993	$ 25,888	89,896	838,506	(102)	$ (351,195)
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 (in shares)						1
Stock-based compensation, net of forfeitures	3,332		3,309			$ 23
Issuance of stock, net (in shares)						160
Issuance of stock, net	771		(2,011)			$ 2,782
Issuance of stock for acquisition (in shares)						2,000
Issuance of stock for acquisition	92,572		57,811			$ 34,761
Repurchase of common stock (in shares)						(45)
Repurchase of common stock	(1,788)					$ (1,788)
Common stock dividends	(10,958)			(10,958)
Actuarial loss, net of tax	24				24
Interest rate swap activity, net of tax	(500)				(500)
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 (loss)	18,983			18,983
Ending balance (in shares) at May. 30, 2020		51,776				18,146
Ending balance at May. 30, 2020	784,810	$ 25,888	200,456	874,911	(967)	$ (315,478)
Beginning balance (in shares) at Feb. 29, 2020		51,776				18,153
Beginning balance at Feb. 29, 2020	801,524	$ 25,888	200,751	890,994	(543)	$ (315,566)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, net of forfeitures (in shares)						0
Stock-based compensation, net of forfeitures	(308)		(315)			$ 7
Issuance of stock, net (in shares)						8
Issuance of stock, net	153		20			$ 133
Repurchase of common stock (in shares)						(1)
Repurchase of common stock	(52)					$ (52)
Common stock dividends	(3,730)			(3,730)
Actuarial loss, net of tax	8				8
Interest rate swap activity, net of tax	(432)				(432)
Net income (loss)	(12,353)			(12,353)
Ending balance (in shares) at May. 30, 2020		51,776				18,146
Ending balance at May. 30, 2020	$ 784,810	$ 25,888	$ 200,456	$ 874,911	$ (967)	$ (315,478)