Supplemental Consolidating Financial Statements - Balance Sheet (Details) - USD ($) $ in Thousands	Jul. 25, 2015	Jul. 26, 2014	Jul. 27, 2013	Jul. 28, 2012
Current assets:
Cash and equivalents	$ 21,289	$ 20,672	$ 18,607	$ 52,581
Accounts receivable, net	315,134	272,741
Costs and estimated earnings in excess of billings	274,730	230,569
Inventories	48,650	49,095
Deferred tax assets, net	20,630	19,932
Other current assets	16,199	12,727
Total current assets	696,632	605,736
Property and equipment, net	231,564	205,413
Goodwill	271,653	269,088	267,810
Intangible assets, net	120,926	116,116
Deferred tax assets, net non-current	0	0
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Other	38,089	16,001
Total non-current assets	662,232	606,618
Total assets	1,358,864	1,212,354
Current liabilities:
Accounts payable	71,834	63,318
Current portion of debt	3,750	10,938
Billings in excess of costs and estimated earnings	16,896	13,882
Accrued insurance claims	35,824	32,260
Deferred tax liabilities	0	0
Other accrued liabilities	98,406	76,134
Total current liabilities	226,710	196,532
Long-term debt	521,841	446,863
Accrued insurance claims	51,476	33,782
Deferred tax liabilities, net non-current	47,388	45,361
Intercompany payables	0	0
Other liabilities	4,249	4,882
Total liabilities	851,664	727,420
Total stockholders' equity	507,200	484,934	428,361	392,931
Total liabilities and stockholders' equity	1,358,864	1,212,354
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	2,939	3,822
Other current assets	7,350	4,956
Total current assets	10,289	8,778
Property and equipment, net	23,527	18,108
Goodwill	0	0
Intangible assets, net	0	0
Deferred tax assets, net non-current	0	182
Investment in subsidiaries	893,940	809,617
Intercompany receivables	0	0
Other	17,460	7,748
Total non-current assets	934,927	835,655
Total assets	945,216	844,433
Current liabilities:
Accounts payable	5,388	3,083
Current portion of debt	3,750	10,938
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	156	612
Deferred tax liabilities	0	0
Other accrued liabilities	22,428	12,668
Total current liabilities	31,722	27,301
Long-term debt	241,500	166,125
Accrued insurance claims	53	778
Deferred tax liabilities, net non-current	1,430	0
Intercompany payables	160,238	162,127
Other liabilities	3,073	3,168
Total liabilities	438,016	359,499
Total stockholders' equity	507,200	484,934
Total liabilities and stockholders' equity	945,216	844,433
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
Other current assets	20	16
Total current assets	20	16
Property and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Deferred tax assets, net non-current	72	0
Investment in subsidiaries	2,348,292	1,540,338
Intercompany receivables	0	0
Other	4,940	5,636
Total non-current assets	2,353,304	1,545,974
Total assets	2,353,324	1,545,990
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	62	80
Other accrued liabilities	504	566
Total current liabilities	566	646
Long-term debt	280,341	280,738
Accrued insurance claims	0	0
Deferred tax liabilities, net non-current	363	432
Intercompany payables	1,178,114	454,557
Other liabilities	0	0
Total liabilities	1,459,384	736,373
Total stockholders' equity	893,940	809,617
Total liabilities and stockholders' equity	2,353,324	1,545,990
Guarantor Subsidiaries
Current assets:
Cash and equivalents	20,515	19,739	18,166	51,563
Accounts receivable, net	312,641	269,760
Costs and estimated earnings in excess of billings	273,544	228,541
Inventories	48,650	49,095
Deferred tax assets, net	17,745	16,193
Other current assets	8,097	7,237
Total current assets	681,192	590,565
Property and equipment, net	187,596	171,158
Goodwill	271,653	269,088
Intangible assets, net	120,926	115,483
Deferred tax assets, net non-current	3,951	3,884
Investment in subsidiaries	0	1,621
Intercompany receivables	1,347,896	628,443
Other	11,598	2,466
Total non-current assets	1,943,620	1,192,143
Total assets	2,624,812	1,782,708
Current liabilities:
Accounts payable	65,458	58,970
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	16,896	13,882
Accrued insurance claims	35,624	31,599
Deferred tax liabilities	11	66
Other accrued liabilities	73,389	61,284
Total current liabilities	191,378	165,801
Long-term debt	0	0
Accrued insurance claims	51,391	32,959
Deferred tax liabilities, net non-current	48,734	48,593
Intercompany payables	0	0
Other liabilities	1,176	1,711
Total liabilities	292,679	249,064
Total stockholders' equity	2,332,133	1,533,644
Total liabilities and stockholders' equity	2,624,812	1,782,708
Non- Guarantor Subsidiaries
Current assets:
Cash and equivalents	774	933	441	1,018
Accounts receivable, net	2,493	2,981
Costs and estimated earnings in excess of billings	1,186	2,028
Inventories	0	0
Deferred tax assets, net	69	87
Other current assets	732	518
Total current assets	5,254	6,547
Property and equipment, net	20,441	16,147
Goodwill	0	0
Intangible assets, net	0	633
Deferred tax assets, net non-current	827	15
Investment in subsidiaries	0	0
Intercompany receivables	0	0
Other	4,091	151
Total non-current assets	25,359	16,946
Total assets	30,613	23,493
Current liabilities:
Accounts payable	988	1,265
Current portion of debt	0	0
Billings in excess of costs and estimated earnings	0	0
Accrued insurance claims	44	49
Deferred tax liabilities	50	24
Other accrued liabilities	2,085	1,616
Total current liabilities	3,167	2,954
Long-term debt	0	0
Accrued insurance claims	32	45
Deferred tax liabilities, net non-current	1,711	417
Intercompany payables	9,544	11,759
Other liabilities	0	3
Total liabilities	14,454	15,178
Total stockholders' equity	16,159	8,315
Total liabilities and stockholders' equity	30,613	23,493
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	(123)	(170)
Other current assets	0	0
Total current assets	(123)	(170)
Property and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Deferred tax assets, net non-current	(4,850)	(4,081)
Investment in subsidiaries	(3,242,232)	(2,351,576)
Intercompany receivables	(1,347,896)	(628,443)
Other	0	0
Total non-current assets	(4,594,978)	(2,984,100)
Total assets	(4,595,101)	(2,984,270)
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	(123)	(170)
Other accrued liabilities	0	0
Total current liabilities	(123)	(170)
Long-term debt	0	0
Accrued insurance claims	0	0
Deferred tax liabilities, net non-current	(4,850)	(4,081)
Intercompany payables	(1,347,896)	(628,443)
Other liabilities	0	0
Total liabilities	(1,352,869)	(632,694)
Total stockholders' equity	(3,242,232)	(2,351,576)
Total liabilities and stockholders' equity	$ (4,595,101)	$ (2,984,270)