Supplemental Consolidating Financial Statements - Income Statement (Details) (USD $) In Thousands, 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 [Abstract]
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:
Cost 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									145,771	104,024	94,622
Depreciation and amortization									85,481	62,693	62,533
Intercompany charges (income), net									0	0	0
Total									1,531,668	1,135,666	994,274
Interest income (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 (BENEFIT) FOR INCOME TAXES									23,011	25,183	12,377
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									35,188	39,378	16,107
EQUITY IN EARNINGS OF SUBSIDIARIES									0	0	0
NET INCOME	14,666	7,199	1,463	11,861	13,282	9,645	3,485	12,966	35,188	39,378	16,107
Foreign currency translation gain									(35)	(161)	130
COMPREHENSIVE INCOME (LOSS)									35,153	39,217	16,237
Parent
Revenues [Abstract]
Contract revenues									0	0	0
EXPENSES:
Cost of earned revenues, excluding depreciation and amortization									0	0	0
General and administrative									44,462	28,048	23,520
Depreciation and amortization									2,920	3,137	3,192
Intercompany charges (income), net									(53,377)	(34,212)	(29,852)
Total									(5,995)	(3,027)	(3,140)
Interest income (expense), net									(5,675)	(3,049)	(3,140)
Loss on debt extinguishment											0
Other income, net									(320)	22	0
INCOME BEFORE INCOME TAXES									0	0	0
PROVISION (BENEFIT) FOR INCOME TAXES									0	0	0
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									0	0	0
EQUITY IN EARNINGS OF SUBSIDIARIES									35,188	39,378	16,107
NET INCOME									35,188	39,378	16,107
Foreign currency translation gain									(35)	(161)	130
COMPREHENSIVE INCOME (LOSS)									35,153	39,217	16,237
Issuer
Revenues [Abstract]
Contract revenues									0	0	0
EXPENSES:
Cost of earned revenues, excluding depreciation and amortization									0	0	0
General and administrative									818	574	648
Depreciation and amortization									0	0	0
Intercompany charges (income), net									0	0	0
Total									818	574	648
Interest income (expense), net									(17,599)	(13,660)	(12,852)
Loss on debt extinguishment											(8,295)
Other income, net									0	0	0
INCOME BEFORE INCOME TAXES									(18,417)	(14,234)	(21,795)
PROVISION (BENEFIT) FOR INCOME TAXES									(7,281)	(5,550)	(9,430)
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									(11,136)	(8,684)	(12,365)
EQUITY IN EARNINGS OF SUBSIDIARIES									46,324	48,062	28,472
NET INCOME									35,188	39,378	16,107
Foreign currency translation gain									(35)	(161)	130
COMPREHENSIVE INCOME (LOSS)									35,153	39,217	16,237
Subsidiary Guarantors
Revenues [Abstract]
Contract revenues									1,594,363	1,186,380	1,025,484
EXPENSES:
Cost of earned revenues, excluding depreciation and amortization									1,288,369	957,449	827,980
General and administrative									89,336	65,185	62,174
Depreciation and amortization									77,595	54,735	54,232
Intercompany charges (income), net									54,720	33,749	29,437
Total									1,510,020	1,111,118	973,823
Interest income (expense), net									(60)	(8)	81
Loss on debt extinguishment											0
Other income, net									4,794	15,281	10,845
INCOME BEFORE INCOME TAXES									89,077	90,535	62,587
PROVISION (BENEFIT) FOR INCOME TAXES									35,214	35,299	27,142
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									53,863	55,236	35,445
EQUITY IN EARNINGS OF SUBSIDIARIES									0	0	0
NET INCOME									53,863	55,236	35,445
Foreign currency translation gain									0	0	0
COMPREHENSIVE INCOME (LOSS)									53,863	55,236	35,445
Non-Guarantor Subsidiaries
Revenues [Abstract]
Contract revenues									14,249	14,739	10,384
EXPENSES:
Cost of earned revenues, excluding depreciation and amortization									12,047	11,500	9,139
General and administrative									11,155	10,217	8,280
Depreciation and amortization									4,966	4,833	5,156
Intercompany charges (income), net									(1,343)	463	415
Total									26,825	27,013	22,990
Interest income (expense), net									0	0	0
Loss on debt extinguishment											0
Other income, net									115	522	251
INCOME BEFORE INCOME TAXES									(12,461)	(11,752)	(12,355)
PROVISION (BENEFIT) FOR INCOME TAXES									(4,922)	(4,566)	(5,335)
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									(7,539)	(7,186)	(7,020)
EQUITY IN EARNINGS OF SUBSIDIARIES									0	0	0
NET INCOME									(7,539)	(7,186)	(7,020)
Foreign currency translation gain									(35)	(161)	130
COMPREHENSIVE INCOME (LOSS)									(7,574)	(7,347)	(6,890)
Eliminations and Reclassifications
Revenues [Abstract]
Contract revenues									0	0	0
EXPENSES:
Cost of earned revenues, excluding depreciation and amortization									0	0	0
General and administrative									0	0	0
Depreciation and amortization									0	(12)	(47)
Intercompany charges (income), net									0	0	0
Total									0	(12)	(47)
Interest income (expense), net									0	0	0
Loss on debt extinguishment											0
Other income, net									0	0	0
INCOME BEFORE INCOME TAXES									0	12	47
PROVISION (BENEFIT) FOR INCOME TAXES									0	0	0
NET INCOME (LOSS) BEFORE EQUITY IN EARNINGS OF SUBSIDIARIES									0	12	47
EQUITY IN EARNINGS OF SUBSIDIARIES									(81,512)	(87,440)	(44,579)
NET INCOME									(81,512)	(87,428)	(44,532)
Foreign currency translation gain									70	322	(260)
COMPREHENSIVE INCOME (LOSS)									$ (81,442)	$ (87,106)	$ (44,792)