Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
OPERATING ACTIVITIES
Net income	$ 87,362	$ 72,324	$ 44,244
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	40,389	32,196	27,915
Interest accretion of convertible notes discount	9,854	9,109	3,589
Financing costs amortization	1,306	1,530	4,383
Call premium related to redemption of long-term debt	0	0	4,964
Employee share-based compensation expense	9,989	7,461	5,433
Loss on disposal of assets	0	0	1,541
Impairment of intangible assets	0	3,070	0
Unrealized foreign currency transaction (gain) loss	(3,388)	96	(180)
Deferred income tax benefit	(1,607)	(4,518)	(2,491)
Reversal of contingent consideration liability	0	(4,620)	0
Other non-cash operating activities	4,514	6,165	(536)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(69,287)	3,422	(34,359)
Inventory	(12,679)	(15,777)	(31,628)
Unbilled contract revenues and other current assets	(10,875)	(7,465)	(10,479)
Accounts payable and other liabilities	(5,259)	2,936	18,129
Deferred income taxes	(793)	663	138
Customer advances and billings in excess of contract revenue	10,137	(18,951)	50,995
Net Cash Provided By Operating Activities	59,663	87,641	81,658
INVESTING ACTIVITIES
Capital expenditures	(72,585)	(43,685)	(22,380)
Proceeds from sale of assets	569	2,073	0
Acquisition of businesses, net of cash acquired	(2,965)	(182,450)	(37,680)
Other investing activities	0	(285)	388
Net Cash Used In Investing Activities	(74,981)	(224,347)	(59,672)
FINANCING ACTIVITIES
Proceeds from long-term debt	0	21,375	0
Borrowings on revolving credit facilities	214,623	73,012	4,758
Repayments on revolving credit facilities	(211,403)	(77,770)	0
Principal payments on long-term debt	(3,750)	(4,438)	(6,500)
Payment of deferred financing costs	0	(1,445)	(7,277)
Retirement of long-term debt, including call premium	0	0	(168,139)
Proceeds from issuance of convertible notes	0	0	250,000
Proceeds from issuance of warrants	0	0	48,848
Payment for call options related to convertible notes	0	0	(66,486)
Payment of contingent consideration	0	(1,300)	(1,300)
Proceeds from exercise of stock options	5,335	3,519	7,027
Tax benefit from exercise of stock options	6,673	8,972	7,879
Common stock repurchases	(2,002)	(4,484)	(1,099)
Dividend distribution to noncontrolling interest	(1,369)	0	0
Net Cash Provided By Financing Activities	8,107	17,441	67,711
Effect of exchange rate changes on cash	3,058	3,902	2,052
Net (decrease) increase in cash and cash equivalents	(4,153)	(115,363)	91,749
Cash and cash equivalents at beginning of period	141,498	256,861	165,112
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 137,345	$ 141,498	$ 256,861