Supplemental Consolidating Financial Statements - Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Jan. 25, 2014	Jul. 27, 2013	Jan. 26, 2013	Dec. 03, 2012	Jul. 28, 2012
CURRENT ASSETS:
Cash and equivalents	$ 16,344	$ 18,607	$ 22,590		$ 52,581
Accounts receivable, net	231,619	252,202
Costs and estimated earnings in excess of billings	174,138	204,349
Inventories	43,426	35,999
Deferred tax assets, net	16,334	16,853
Income taxes receivable	18,347	2,516
Other current assets	16,142	10,608
Total current assets	516,350	541,134
PROPERTY AND EQUIPMENT, NET	203,639	202,703
GOODWILL	267,810	267,810		87,900
INTANGIBLE ASSETS, NET	115,243	125,275
DEFERRED TAX ASSETS, NET NON-CURRENT	0	0
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	0	0
OTHER	16,852	17,286
TOTAL NON-CURRENT ASSETS	603,544	613,074
TOTAL ASSETS	1,119,894	1,154,208
CURRENT LIABILITIES:
Accounts payable	52,315	77,954
Current portion of debt	9,375	7,813
Billings in excess of costs and estimated earnings	13,869	13,788
Accrued insurance claims	32,638	29,069
Deferred Tax Liabilities, Net, Current	0	0
Other accrued liabilities	57,566	71,191
Total current liabilities	165,763	199,815
Long-term debt	416,301	444,169
ACCRUED INSURANCE CLAIMS	30,942	27,250
DEFERRED TAX LIABILITIES, NET NON-CURRENT	49,003	48,612
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	6,249	6,001
Total liabilities	668,258	725,847
Total stockholders' equity	451,636	428,361
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,119,894	1,154,208
Parent
CURRENT ASSETS:
Cash and equivalents	0	0	0		0
Accounts receivable, net	0	0
Costs and estimated earnings in excess of billings	0	0
Inventories	0	0
Deferred tax assets, net	2,543	2,285
Income taxes receivable	18,347	2,516
Other current assets	8,503	2,563
Total current assets	29,393	7,364
PROPERTY AND EQUIPMENT, NET	16,402	13,779
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	59	691
INVESTMENT IN SUBSIDIARIES	785,232	769,639
INTERCOMPANY RECEIVABLES	0	0
OTHER	8,554	8,739
TOTAL NON-CURRENT ASSETS	810,247	792,848
TOTAL ASSETS	839,640	800,212
CURRENT LIABILITIES:
Accounts payable	2,607	2,042
Current portion of debt	9,375	7,813
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	620	619
Deferred Tax Liabilities, Net, Current	0	0
Other accrued liabilities	6,663	9,151
Total current liabilities	19,265	19,625
Long-term debt	135,375	163,062
ACCRUED INSURANCE CLAIMS	743	726
DEFERRED TAX LIABILITIES, NET NON-CURRENT	0	0
INTERCOMPANY PAYABLES	229,350	185,296
OTHER LIABILITIES	3,271	3,142
Total liabilities	388,004	371,851
Total stockholders' equity	451,636	428,361
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	839,640	800,212
Issuer
CURRENT ASSETS:
Cash and equivalents	0	0	0		0
Accounts receivable, net	0	0
Costs and estimated earnings in excess of billings	0	0
Inventories	0	0
Deferred tax assets, net	0	0
Income taxes receivable	0	0
Other current assets	44	10
Total current assets	44	10
PROPERTY AND EQUIPMENT, NET	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	0	0
INVESTMENT IN SUBSIDIARIES	1,502,749	1,472,559
INTERCOMPANY RECEIVABLES	0	0
OTHER	5,976	6,331
TOTAL NON-CURRENT ASSETS	1,508,725	1,478,890
TOTAL ASSETS	1,508,769	1,478,900
CURRENT LIABILITIES:
Accounts payable	0	0
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	0	0
Deferred Tax Liabilities, Net, Current	155	155
Other accrued liabilities	607	1,321
Total current liabilities	762	1,476
Long-term debt	280,926	281,107
ACCRUED INSURANCE CLAIMS	0	0
DEFERRED TAX LIABILITIES, NET NON-CURRENT	427	427
INTERCOMPANY PAYABLES	441,422	426,251
OTHER LIABILITIES	0	0
Total liabilities	723,537	709,261
Total stockholders' equity	785,232	769,639
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,508,769	1,478,900
Subsidiary Guarantors
CURRENT ASSETS:
Cash and equivalents	15,212	18,166	21,528		51,563
Accounts receivable, net	230,775	249,533
Costs and estimated earnings in excess of billings	172,989	202,651
Inventories	43,426	35,999
Deferred tax assets, net	14,043	15,873
Income taxes receivable	0	0
Other current assets	7,248	7,583
Total current assets	483,693	529,805
PROPERTY AND EQUIPMENT, NET	172,637	173,254
GOODWILL	267,810	267,810
INTANGIBLE ASSETS, NET	115,243	125,275
DEFERRED TAX ASSETS, NET NON-CURRENT	4,122	4,104
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	681,310	618,524
OTHER	2,087	2,133
TOTAL NON-CURRENT ASSETS	1,243,209	1,191,100
TOTAL ASSETS	1,726,902	1,720,905
CURRENT LIABILITIES:
Accounts payable	49,046	75,012
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	13,869	13,788
Accrued insurance claims	31,953	28,342
Deferred Tax Liabilities, Net, Current	150	140
Other accrued liabilities	49,018	59,374
Total current liabilities	144,036	176,656
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	30,134	26,426
DEFERRED TAX LIABILITIES, NET NON-CURRENT	53,005	52,436
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	2,829	2,855
Total liabilities	230,004	258,373
Total stockholders' equity	1,496,898	1,462,532
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,726,902	1,720,905
Non-Guarantor Subsidiaries
CURRENT ASSETS:
Cash and equivalents	1,132	441	1,062		1,018
Accounts receivable, net	844	2,669
Costs and estimated earnings in excess of billings	1,149	1,698
Inventories	0	0
Deferred tax assets, net	80	121
Income taxes receivable	0	0
Other current assets	347	452
Total current assets	3,552	5,381
PROPERTY AND EQUIPMENT, NET	14,600	15,670
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	839	66
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	0	0
OTHER	235	83
TOTAL NON-CURRENT ASSETS	15,674	15,819
TOTAL ASSETS	19,226	21,200
CURRENT LIABILITIES:
Accounts payable	662	900
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	65	108
Deferred Tax Liabilities, Net, Current	27	1,131
Other accrued liabilities	1,278	1,345
Total current liabilities	2,032	3,484
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	65	98
DEFERRED TAX LIABILITIES, NET NON-CURRENT	591	610
INTERCOMPANY PAYABLES	10,538	6,977
OTHER LIABILITIES	149	4
Total liabilities	13,375	11,173
Total stockholders' equity	5,851	10,027
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	19,226	21,200
Eliminations and Reclassifications
CURRENT ASSETS:
Cash and equivalents	0	0	0		0
Accounts receivable, net	0	0
Costs and estimated earnings in excess of billings	0	0
Inventories	0	0
Deferred tax assets, net	(332)	(1,426)
Income taxes receivable	0	0
Other current assets	0	0
Total current assets	(332)	(1,426)
PROPERTY AND EQUIPMENT, NET	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	(5,020)	(4,861)
INVESTMENT IN SUBSIDIARIES	(2,287,981)	(2,242,198)
INTERCOMPANY RECEIVABLES	(681,310)	(618,524)
OTHER	0	0
TOTAL NON-CURRENT ASSETS	(2,974,311)	(2,865,583)
TOTAL ASSETS	(2,974,643)	(2,867,009)
CURRENT LIABILITIES:
Accounts payable	0	0
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	0	0
Deferred Tax Liabilities, Net, Current	(332)	(1,426)
Other accrued liabilities	0	0
Total current liabilities	(332)	(1,426)
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	0	0
DEFERRED TAX LIABILITIES, NET NON-CURRENT	(5,020)	(4,861)
INTERCOMPANY PAYABLES	(681,310)	(618,524)
OTHER LIABILITIES	0	0
Total liabilities	(686,662)	(624,811)
Total stockholders' equity	(2,287,981)	(2,242,198)
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ (2,974,643)	$ (2,867,009)