Condensed Unaudited Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 99,621		$ 71,076
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	103,111		65,767
Non-cash stock-based compensation expense	9,647		3,351
Non-cash interest expense	6,890		6,424
Write-off of unamortized financing costs on redeemed debt	1,508		0
Gains on sales of assets	(4,884)		(1,569)
Excess tax benefit from non-cash stock-based compensation	(4,446)	[1]	(302)	[1]
Loss on disposal and impairment charges, discontinued operations	6,036		12,922
Changes in assets and liabilities, net of assets acquired and liabilities assumed:
Accounts receivable	(271,010)		(233,220)
Inventories	20,484		8,243
Deferred tax assets and liabilities, net	9,783		(3,555)
Other assets, current and non-current portion	19,117		(6,383)
Accounts payable and accrued expenses	126,784		176,289
Billings in excess of costs and earnings	(19,776)		(3,367)
Other liabilities, current and non-current portion	13,701		25,099
Net cash provided by operating activities	124,991		114,670
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net, including contingent consideration	(159,446)		(17,496)
Capital expenditures	(101,411)		(50,331)
Proceeds from sale of property and equipment	8,288		5,808
Proceeds from sale or redemption of investments	5,025		0
Proceeds from disposal of business, net of cash divested	(4,332)		97,728
Payments for other investments, net	(1,174)		(284)
Net cash (used in) provided by investing activities	(253,050)		35,425
Cash flows provided by (used in) financing activities:
Proceeds from issuance of 4.875% senior notes	400,000		0
Repayment of 7.625% senior notes	(150,000)		0
Proceeds from credit facility	766,154		631,815
Repayments of credit facility	(860,070)		(681,815)
Repayments of other borrowings	(24,246)		(15,510)
Proceeds from (repayments of) book overdrafts	2,791		(5,645)
Payments of capital lease obligations	(32,214)		(14,806)
Proceeds from stock option exercises and other share-based awards	9,231		1,445
Excess tax benefit from non-cash stock-based compensation	4,446		302
Purchases of treasury stock	0		(75,000)
Payments for debt extinguishment, call premiums	(4,116)		0
Payments of financing costs	(7,718)		(113)
Net cash provided by (used in) financing activities	104,258		(159,327)
Net decrease in cash and cash equivalents	(23,801)		(9,232)
Net effect of currency translation on cash	(118)		135
Cash and cash equivalents - beginning of period	26,767		20,279
Cash and cash equivalents - end of period	2,848		11,182
Cash and cash equivalents of discontinued operations	0		710
Cash and cash equivalents of continuing operations	2,848		10,472
Supplemental cash flow information:
Interest paid	30,851		20,879
Income taxes paid, net of refunds	49,722		37,219
Supplemental disclosure of non-cash investing and financing information:
Equipment acquired under capital lease	82,737		29,917
Common Stock Outstanding [Member] | Investor [Member]
Supplemental cash flow information:
Non-cash transaction, value of consideration received	6,002		0
Machinery and Equipment [Member]
Supplemental disclosure of non-cash investing and financing information:
Equipment acquired under financing arrangements	24,100		4,887
Accounts Receivable [Member] | Machinery and Equipment [Member]
Supplemental cash flow information:
Non-cash transaction, value of consideration received	9,683		0
Inventories [Member]
Supplemental cash flow information:
Non-cash transaction, value of consideration received	0		12,005
Operating Expense [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Provisions for losses on assets	6,300		4,226
Contracts Accounted for under Percentage of Completion [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for losses on construction projects, net	$ 2,125		$ (10,331)

[1] Excess tax benefits, which represent cash flows from tax deductions in excess of the tax effect of compensation expense recognized for stock options exercised and vested restricted shares, are classified as financing cash flows in the Company’s condensed unaudited consolidated statements of cash flows.