Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Cash Flows from Operating Activities:
Net income	$ 74,726	$ 69,797	$ 151,583	$ 119,791
Income from discontinued operations		(7,620)		(7,529)
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation	33,040	29,376	64,920	58,402
Amortization of intangible assets	5,079	9,326	10,380	18,491
Amortization of debt issuance costs	218	227	436	450
Amortization of deferred revenues	(3,012)	(2,554)	(5,517)	(5,140)
Gain on sale of property and equipment	(371)	(584)	(653)	(447)
Foreign currency loss	442	647	944	374
Provision for doubtful accounts	154	623	1,662	2,359
Deferred income tax provision	6,096	4,664	4,974	9,652
Non-cash stock-based compensation	12,042	7,597	20,078	13,486
Tax impact of stock-based equity awards	(2,568)	2,868	(2,568)	(42)
Changes in operating assets and liabilities, net of non-cash transactions - (Increase) decrease in -
Accounts and notes receivable	(1,684)	1,420	29,159	(37,171)
Costs and estimated earnings in excess of billings on uncompleted contracts	(638)	(35,899)	(65,668)	(139,290)
Inventories	(3,393)	19,256	(2,896)	22,458
Prepaid expenses and other current assets	1,880	(667)	15,428	6,201
Increase (decrease) in -
Accounts payable and accrued expenses and other non-current liabilities	(29,896)	38,578	(77,530)	(6,957)
Billings in excess of costs and estimated earnings on uncompleted contracts	26,518	(29,789)	16,014	(18,860)
Other, net	(857)	369	1,162	(2,074)
Net cash provided by operating activities of continuing operations	117,776	107,635	161,908	34,154
Cash Flows from Investing Activities:
Proceeds from sale of property and equipment	2,555	6,256	4,099	6,869
Additions of property and equipment	(81,743)	(44,866)	(139,380)	(76,734)
Cash paid for acquisitions, net of cash acquired		(26,823)	(977)	(68,727)
Investments in unconsolidated affiliates	(925)	(48,844)	(9,470)	(53,750)
Cash paid for other investments	(36,112)		(36,112)
Net cash used in investing activities of continuing operations	(116,225)	(114,277)	(181,840)	(192,342)
Cash Flows from Financing Activities:
Borrowings under credit facility		349,620		349,620
Payments under credit facility		(310,620)		(310,620)
Payments on other long-term debt		(33)		(33)
Distributions to noncontrolling interests	(3,858)	(3,747)	(9,312)	(6,237)
Tax impact of stock-based equity awards	2,568	(2,868)	2,568	42
Exercise of stock options	326	445	823	924
Net cash provided by (used in) financing activities of continuing operations	(964)	32,797	(5,921)	33,696
Discontinued operations:
Net cash used in operating activities		(21,336)		(8,073)
Net cash used in investing activities		(5,109)		(7,999)
Net cash used in discontinued operations		(26,445)		(16,072)
Effect of foreign exchange rate changes on cash and cash equivalents	(4,093)	(4,209)	(5,735)	(1,917)
Net decrease in cash and cash equivalents	(3,506)	(4,499)	(31,588)	(142,481)
Cash and cash equivalents, beginning of period	366,619	177,367	394,701	315,349
Cash and cash equivalents, end of period	363,113	172,868	363,113	172,868
Cash (paid) received during the period for -
Interest paid	(267)	(424)	(729)	(780)
Income taxes paid	(65,809)	(23,330)	(157,390)	(70,924)
Income tax refunds	$ 336	$ 988	$ 342	$ 2,293