Condensed Unaudited Consolidated Statements of Cash Flows - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income (loss)		$ 78,086	$ (2,766)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization		122,249	128,048
Non-cash interest expense, net		2,209	2,036
Non-cash stock-based compensation expense		11,291	9,486
Excess tax benefit from stock-based compensation	[1]	(1,385)	(56)
Benefit from deferred income taxes		(1,339)	(9,076)
Other non-cash items		3,336	1,783
Losses (gains) on sales of assets, including estimated losses on fixed assets held-for-sale		378	(2,619)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable		(302,590)	252,333
Inventories		(18,900)	22,406
Other assets, current and long-term portion		44,483	(13,915)
Accounts payable and accrued expenses		172,731	(76,747)
Billings in excess of costs and earnings		16,581	(31,168)
Book overdrafts		8,883	(7,830)
Other liabilities, current and long-term portion		(8,872)	(11,313)
Net cash provided by operating activities		127,141	260,602
Cash flows used in investing activities:
Cash paid for acquisitions, net of cash acquired		(4,102)	(148)
Capital expenditures		(89,050)	(70,766)
Proceeds from sale of property and equipment		6,824	9,763
Payments for other investments, net		(7,733)	(109,299)
Net cash used in investing activities		(94,061)	(170,450)
Cash flows provided by (used in) financing activities:
Proceeds from credit facilities		1,186,816	1,329,610
Repayments of credit facilities		(1,149,930)	(1,240,122)
Repayments of other borrowings		(8,188)	(10,568)
Payments of capital lease obligations		(41,828)	(40,687)
Repurchase of common stock		0	(100,000)
Proceeds from stock-based awards, net		3,938	1,743
Excess tax benefit from stock-based compensation		1,385	56
Payments of acquisition-related contingent consideration		(19,822)	(44,757)
Payments of financing costs		0	(2,435)
Net cash used in financing activities		(27,629)	(107,160)
Effect of currency translation on cash		(1,008)	103
Net increase (decrease) in cash and cash equivalents		4,443	(16,905)
Cash and cash equivalents - beginning of period		4,984	24,059
Cash and cash equivalents - end of period		9,427	7,154
Supplemental cash flow information:
Interest paid		40,433	41,014
Income taxes paid, net of refunds		15,141	5,841
Supplemental disclosure of non-cash information:
Equipment acquired under capital lease		13,015	18,030
Accrued capital expenditures		4,119	2,191
Equipment [Member]
Supplemental disclosure of non-cash information:
Equipment acquired under financing arrangements		$ 0	$ 5,758

[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.