CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 27, 2012	Oct. 29, 2011
OPERATING ACTIVITIES:
Net income	$ 11,861	$ 12,966
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,311	15,958
Bad debt expense, net	9	36
Gain on sale of fixed assets	(1,581)	(2,918)
Deferred income tax provision	(1,217)	3,520
Stock-based compensation	2,266	1,326
Amortization of debt issuance costs	329	323
Excess tax benefit from share-based awards	(64)	(175)
Change in operating assets and liabilities:
Accounts receivable, net	(12,015)	(2,047)
Costs and estimated earnings in excess of billings, net	8,838	(10,864)
Other current assets and inventory	(3,509)	(8,305)
Other assets	(62)	288
Income taxes receivable/payable	8,773	5,398
Accounts payable	3,879	3,563
Accrued liabilities, insurance claims, and other liabilities	(5,102)	364
Net cash provided by operating activities	27,716	19,433
INVESTING ACTIVITIES:
Capital expenditures	(12,523)	(20,857)
Proceeds from sale of assets	2,006	6,417
Changes in restricted cash	0	550
Net cash used in investing activities	(10,517)	(13,890)
FINANCING ACTIVITIES:
Repurchases of common stock	(15,203)	0
Exercise of stock options and other	166	940
Restricted stock tax withholdings	(62)	(37)
Excess tax benefit from share-based awards	64	175
Principal payments on capital lease obligations	(19)	(75)
Net cash (used in) provided by financing activities	(15,054)	1,003
Net increase in cash and equivalents	2,145	6,546
CASH AND EQUIVALENTS AT BEGINNING OF PERIOD	52,581	44,766
CASH AND EQUIVALENTS AT END OF PERIOD	54,726	51,312
Cash paid during the period for:
Interest	489	511
Income taxes	85	632
Purchases of capital assets included in accounts payable or other accrued liabilities at period end	$ 2,364	$ 2,893