Condensed Unaudited Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013
Cash flows from operating activities:
Net income	$ 47,982		$ 53,420
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	70,249		65,355
Non-cash interest expense, including write-off of deferred financing costs on redeemed debt	4,642		6,036
Non-cash stock-based compensation expense	7,480		6,617
Excess tax benefit from stock-based compensation	(3,386)	[1]	(1,462)	[1]
Provision for deferred income taxes	11,160		7,109
(Gains) losses on sales of assets, including impairment charges on discontinued operations	(2,593)		(1,752)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(21,270)		(178,566)
Inventories	(37,140)		17,124
Other assets, current and non-current portion	4,655		16,593
Accounts payable and accrued expenses	(8,916)		14,869
Billings in excess of costs and earnings	(12,258)		8,046
Book overdrafts	(1,355)		7,989
Other liabilities, current and non-current portion	(3,391)		(2,759)
Net cash provided by operating activities	55,319		22,857
Cash flows (used in) provided by investing activities:
Cash paid for acquisitions, net of cash acquired	(162,901)		(120,544)
Capital expenditures	(67,566)		(57,527)
Proceeds from sale of property and equipment	8,752		5,123
Proceeds from other investments, net	573		4,931
Net cash used in investing activities	(221,142)		(168,017)
Cash flows provided by (used in) financing activities:
Proceeds from credit facility	815,840		499,666
Repayments of credit facility	(463,713)		(558,596)
Proceeds from issuance of senior notes	0		400,000
Repayment of senior notes, including convertible notes	(105,325)		(150,000)
Repayments of other borrowings	(7,220)		(18,570)
Payments of capital lease obligations	(23,023)		(21,139)
Excess tax benefit from stock-based compensation	3,386		1,462
Payments of financing costs, including call premiums on extinguishment of debt	(1,298)		(11,685)
Net cash provided by financing activities	159,167		132,272
Net decrease in cash and cash equivalents	(6,656)		(12,888)
Net effect of currency translation on cash	(347)		(274)
Cash and cash equivalents - beginning of period	22,927		26,767
Cash and cash equivalents - end of period	15,924		13,605
Cash and cash equivalents of discontinued operations	0		310
Cash and cash equivalents of continuing operations	15,924		13,295
Supplemental cash flow information:
Interest paid	20,247		17,801
Income taxes paid, net of refunds	29,901		41,625
Supplemental disclosure of non-cash information:
Equipment acquired under capital lease	44,574		56,622
2011 4.0% Notes [Member]
Cash flows provided by (used in) financing activities:
Repayment of senior notes, including convertible notes	(105,300)
Supplemental disclosure of non-cash information:
Value of premium shares issued for convertible notes	114,785		0
Equipment [Member]
Supplemental disclosure of non-cash information:
Equipment acquired under financing arrangements	5,780		23,406
Earn-Out Arrangements [Member]
Cash flows provided by (used in) financing activities:
Payments of acquisition-related contingent consideration	(58,902)		(12,848)
Supplemental disclosure of non-cash information:
Value of acquisition-related contingent consideration	33,612		26,721
Stock Compensation Plan [Member]
Cash flows provided by (used in) financing activities:
Payments of tax withholdings and proceeds from stock-based awards, net	(578)		3,982
Payments of acquisition-related contingent consideration	2,800		5,400
Operating Expense [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for losses on operating assets	438		2,851
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	$ (978)		$ 1,387

[1] Excess tax benefits, which represent cash flows from tax deductions in excess of the recorded 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.