CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jul. 27, 2013	Apr. 27, 2013	Jan. 26, 2013	Oct. 27, 2012	Jul. 28, 2012	Apr. 28, 2012	Jan. 28, 2012	Oct. 29, 2011	Jul. 27, 2013	Jul. 28, 2012	Jul. 30, 2011
REVENUES:
Contract revenues	$ 478,632	$ 437,367	$ 369,326	$ 323,286	$ 318,034	$ 296,103	$ 267,407	$ 319,575	$ 1,608,612	$ 1,201,119	$ 1,035,868
EXPENSES:
Costs of earned revenues, excluding depreciation and amortization	384,169	357,664	301,516	257,066	252,137	241,386	220,239	255,187	1,300,416	968,949	837,119
General and administrative (including stock-based compensation expense of $9.9 million, $7.0 million, and $4.4 million, respectively)									145,771	104,024	94,622
Depreciation and amortization									85,481	62,693	62,533
Total									1,531,668	1,135,666	994,274
Interest expense, net									(23,334)	(16,717)	(15,911)
Loss on debt extinguishment									0	0	(8,295)
Other income, net									4,589	15,825	11,096
INCOME BEFORE INCOME TAXES									58,199	64,561	28,484
PROVISION FOR INCOME TAXES:
Current									25,281	15,309	(2,351)
Deferred									(2,270)	9,874	14,728
Total									23,011	25,183	12,377
NET INCOME	$ 14,666	$ 7,199	$ 1,463	$ 11,861	$ 13,282	$ 9,645	$ 3,485	$ 12,966	$ 35,188	$ 39,378	$ 16,107
Earnings Per Common Share:
Basic earnings per common share	$ 0.44	$ 0.22	$ 0.04	$ 0.36	$ 0.40	$ 0.29	$ 0.10	$ 0.39	$ 1.07	$ 1.17	$ 0.46
Diluted earnings per common share	$ 0.43	$ 0.21	$ 0.04	$ 0.35	$ 0.39	$ 0.28	$ 0.10	$ 0.38	$ 1.04	$ 1.14	$ 0.45
SHARES USED IN COMPUTING EARNINGS PER COMMON SHARE:
Basic									33,012,595	33,653,055	35,306,900
Diluted									33,782,187	34,481,895	35,754,168