Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net (loss) income		$ (10,208)	$ 45,730
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization		85,852	70,249
Non-cash interest expense		1,324	4,642
Non-cash stock-based compensation expense		6,320	7,480
Excess tax benefit from stock-based compensation	[1]	(53)	(3,386)
(Benefit from) provision for deferred income taxes		(10,026)	11,160
Other non-cash items		736	438
Gains on sales of assets		(1,427)	(2,593)
Non-cash change in estimated fair value of acquisition-related contingent consideration		(3,601)	0
Changes in assets and liabilities, net of acquisitions:
Accounts receivable		159,384	(12,848)
Inventories		9,356	(37,140)
Other assets, current and long-term portion		5,587	3,273
Accounts payable and accrued expenses		(37,335)	(8,816)
Billings in excess of costs and earnings		(33,100)	(13,095)
Book overdrafts		1,217	(1,355)
Other liabilities, current and long-term portion		(8,173)	(8,420)
Net cash provided by operating activities		165,853	55,319
Cash flows used in investing activities:
Cash paid for acquisitions, net of cash acquired		(148)	(162,901)
Capital expenditures		(48,431)	(67,566)
Proceeds from sale of property and equipment		4,146	8,752
Payments for other investments, net		(69,795)	573
Net cash used in investing activities		(114,228)	(221,142)
Cash flows (used in) provided by financing activities:
Proceeds from credit facilities		844,494	815,840
Repayments of credit facilities		(741,302)	(463,713)
Repayments of senior convertible notes		0	(105,325)
Repayments of other borrowings		(6,683)	(7,220)
Payments of capital lease obligations		(28,469)	(23,023)
Repurchase of common stock		(100,000)	0
Proceeds from stock-based awards, net of tax withholdings		1,849	(578)
Excess tax benefit from stock-based compensation		53	3,386
Payments of acquisition-related contingent consideration		(39,257)	(58,902)
Payments of financing costs		(1,053)	(1,298)
Net cash (used in) provided by financing activities		(70,368)	159,167
Effect of currency translation on cash		(561)	(347)
Net decrease in cash and cash equivalents		(19,304)	(7,003)
Cash and cash equivalents - beginning of period		24,059	22,927
Cash and cash equivalents - end of period		4,755	15,924
Supplemental cash flow information:
Interest paid		22,837	20,247
Income taxes paid, net of refunds		5,429	29,901
Supplemental disclosure of non-cash information:
Equipment acquired under capital lease		16,084	44,574
2011 Convertible Notes [Member]
Supplemental disclosure of non-cash information:
Premium shares, conversion of convertible notes			114,785
Earn-Out Arrangements [Member]
Supplemental disclosure of non-cash information:
Acquisition-related contingent consideration, new business combinations			33,612
Equipment [Member]
Supplemental disclosure of non-cash information:
Equipment acquired under financing arrangements		$ 11,062	$ 5,780

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