Supplemental Consolidating Financial Statements - Balance Sheet (Details) (USD $) In Thousands, unless otherwise specified	Oct. 26, 2013	Jul. 27, 2013	Dec. 03, 2012	Oct. 27, 2012	Jul. 28, 2012
CURRENT ASSETS:
Cash and equivalents	$ 14,394	$ 18,607		$ 54,726	$ 52,581
Accounts receivable, net	304,412	252,202
Costs and estimated earnings in excess of billings	221,110	204,349
Inventories	39,273	35,999
Deferred tax assets, net	17,718	16,853
Income taxes receivable	2,231	2,516
Other current assets	16,192	10,608
Total current assets	615,330	541,134
PROPERTY AND EQUIPMENT, NET	203,916	202,703
GOODWILL	267,810	267,810	87,900
INTANGIBLE ASSETS, NET	120,021	125,275
DEFERRED TAX ASSETS, NET NON-CURRENT	0	0
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	0	0
OTHER	17,199	17,286
TOTAL NON-CURRENT ASSETS	608,946	613,074
TOTAL ASSETS	1,224,276	1,154,208
CURRENT LIABILITIES:
Accounts payable	68,926	77,954
Current portion of debt	8,594	7,813
Billings in excess of costs and estimated earnings	13,347	13,788
Accrued insurance claims	31,528	29,069
Deferred Tax Liabilities, Net, Current	0	0
Other accrued liabilities	79,453	71,191
Total current liabilities	201,848	199,815
Long-term debt	475,735	444,169
ACCRUED INSURANCE CLAIMS	30,114	27,250
DEFERRED TAX LIABILITIES, NET NON-CURRENT	49,603	48,612
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	5,992	6,001
Total liabilities	763,292	725,847
Total stockholders' equity	460,984	428,361
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,224,276	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	2,434	2,285
Income taxes receivable	2,231	2,516
Other current assets	8,446	2,563
Total current assets	13,111	7,364
PROPERTY AND EQUIPMENT, NET	14,666	13,779
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	84	691
INVESTMENT IN SUBSIDIARIES	788,300	769,639
INTERCOMPANY RECEIVABLES	0	0
OTHER	8,883	8,739
TOTAL NON-CURRENT ASSETS	811,933	792,848
TOTAL ASSETS	825,044	800,212
CURRENT LIABILITIES:
Accounts payable	3,639	2,042
Current portion of debt	8,594	7,813
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	618	619
Deferred Tax Liabilities, Net, Current	0	0
Other accrued liabilities	15,986	9,151
Total current liabilities	28,837	19,625
Long-term debt	194,719	163,062
ACCRUED INSURANCE CLAIMS	738	726
DEFERRED TAX LIABILITIES, NET NON-CURRENT	0	0
INTERCOMPANY PAYABLES	136,610	185,296
OTHER LIABILITIES	3,156	3,142
Total liabilities	364,060	371,851
Total stockholders' equity	460,984	428,361
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	825,044	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	55	10
Total current assets	55	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	1,494,353	1,472,559
INTERCOMPANY RECEIVABLES	0	0
OTHER	6,153	6,331
TOTAL NON-CURRENT ASSETS	1,500,506	1,478,890
TOTAL ASSETS	1,500,561	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	5,560	1,321
Total current liabilities	5,715	1,476
Long-term debt	281,016	281,107
ACCRUED INSURANCE CLAIMS	0	0
DEFERRED TAX LIABILITIES, NET NON-CURRENT	427	427
INTERCOMPANY PAYABLES	425,103	426,251
OTHER LIABILITIES	0	0
Total liabilities	712,261	709,261
Total stockholders' equity	788,300	769,639
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,500,561	1,478,900
Subsidiary Guarantors
CURRENT ASSETS:
Cash and equivalents	13,631	18,166		54,096	51,563
Accounts receivable, net	303,178	249,533
Costs and estimated earnings in excess of billings	218,997	202,651
Inventories	39,273	35,999
Deferred tax assets, net	16,573	15,873
Income taxes receivable	0	0
Other current assets	7,189	7,583
Total current assets	598,841	529,805
PROPERTY AND EQUIPMENT, NET	173,353	173,254
GOODWILL	267,810	267,810
INTANGIBLE ASSETS, NET	120,021	125,275
DEFERRED TAX ASSETS, NET NON-CURRENT	4,224	4,104
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	571,013	618,524
OTHER	2,073	2,133
TOTAL NON-CURRENT ASSETS	1,138,494	1,191,100
TOTAL ASSETS	1,737,335	1,720,905
CURRENT LIABILITIES:
Accounts payable	64,623	75,012
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	13,347	13,788
Accrued insurance claims	30,829	28,342
Deferred Tax Liabilities, Net, Current	89	140
Other accrued liabilities	56,596	59,374
Total current liabilities	165,484	176,656
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	29,290	26,426
DEFERRED TAX LIABILITIES, NET NON-CURRENT	53,119	52,436
INTERCOMPANY PAYABLES	0	0
OTHER LIABILITIES	2,832	2,855
Total liabilities	250,725	258,373
Total stockholders' equity	1,486,610	1,462,532
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	1,737,335	1,720,905
Non-Guarantor Subsidiaries
CURRENT ASSETS:
Cash and equivalents	763	441		630	1,018
Accounts receivable, net	1,234	2,669
Costs and estimated earnings in excess of billings	2,113	1,698
Inventories	0	0
Deferred tax assets, net	96	121
Income taxes receivable	0	0
Other current assets	502	452
Total current assets	4,708	5,381
PROPERTY AND EQUIPMENT, NET	15,897	15,670
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	162	66
INVESTMENT IN SUBSIDIARIES	0	0
INTERCOMPANY RECEIVABLES	0	0
OTHER	90	83
TOTAL NON-CURRENT ASSETS	16,149	15,819
TOTAL ASSETS	20,857	21,200
CURRENT LIABILITIES:
Accounts payable	664	900
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	81	108
Deferred Tax Liabilities, Net, Current	1,141	1,131
Other accrued liabilities	1,311	1,345
Total current liabilities	3,197	3,484
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	86	98
DEFERRED TAX LIABILITIES, NET NON-CURRENT	527	610
INTERCOMPANY PAYABLES	9,300	6,977
OTHER LIABILITIES	4	4
Total liabilities	13,114	11,173
Total stockholders' equity	7,743	10,027
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	20,857	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	(1,385)	(1,426)
Income taxes receivable	0	0
Other current assets	0	0
Total current assets	(1,385)	(1,426)
PROPERTY AND EQUIPMENT, NET	0	0
GOODWILL	0	0
INTANGIBLE ASSETS, NET	0	0
DEFERRED TAX ASSETS, NET NON-CURRENT	(4,470)	(4,861)
INVESTMENT IN SUBSIDIARIES	(2,282,653)	(2,242,198)
INTERCOMPANY RECEIVABLES	(571,013)	(618,524)
OTHER	0	0
TOTAL NON-CURRENT ASSETS	(2,858,136)	(2,865,583)
TOTAL ASSETS	(2,859,521)	(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	(1,385)	(1,426)
Other accrued liabilities	0	0
Total current liabilities	(1,385)	(1,426)
Long-term debt	0	0
ACCRUED INSURANCE CLAIMS	0	0
DEFERRED TAX LIABILITIES, NET NON-CURRENT	(4,470)	(4,861)
INTERCOMPANY PAYABLES	(571,013)	(618,524)
OTHER LIABILITIES	0	0
Total liabilities	(576,868)	(624,811)
Total stockholders' equity	(2,282,653)	(2,242,198)
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ (2,859,521)	$ (2,867,009)