Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
OPERATING ACTIVITIES
Net income (loss)	$ 29,500		$ 24,700	$ (204,500)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	41,900		37,500	45,400
Asset impairments	0		1,200	255,100
Interest accretion of convertible notes discount	12,800		12,500	11,500
Loss on extinguishment of debt	4,900		0	0
Financing costs amortization	(1,279)		(1,284)	(1,290)
Employee share-based compensation expense	11,100		10,700	11,300
Unrealized foreign currency transaction loss	300		500	100
Deferred income tax benefit	(29,800)		(2,600)	(24,400)
Other non-cash operating activities	2,300		1,300	800
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(37,100)		43,600	7,200
Inventory	(11,700)		25,700	12,000
Unbilled contract revenues and other assets	6,600		20,800	12,300
Accounts payable and other liabilities	(1,500)		(11,500)	(17,400)
Customer advances and billings in excess of contract revenue	16,400		5,100	(9,700)
Net Cash Provided By Operating Activities	47,000		170,800	101,000
INVESTING ACTIVITIES
Acquisition of businesses, net of cash acquired	(446,100)		(1,400)	(24,500)
Capital expenditures	(35,200)		(17,800)	(47,100)
Payments for China land use rights	0		0	(11,000)
Government grants	400		1,100	8,700
Proceeds from sale of assets	900		0	400
Net Cash Used In Investing Activities	(480,000)		(18,100)	(73,500)
FINANCING ACTIVITIES
Borrowings on revolving credit facilities	302,200		3,800	68,800
Repayments on revolving credit facilities	(66,100)		(6,100)	(67,200)
Repurchase of convertible notes	(194,900)		0	0
Proceeds from issuance of convertible notes	258,800		0	0
Proceeds from issuance of warrants	46,000		0	0
Payments for call options related to convertible notes	(59,500)		0	0
Borrowings on term loan	0		13,200	0
Repayments on term loan	(3,100)		(2,900)	0
Payments for debt issuance costs	(8,200)		0	0
Payment of contingent consideration	0		0	(600)
Proceeds from exercise of stock options	2,000		400	500
Excess tax benefit from share-based compensation	0		0	100
Common stock repurchases	(2,000)		(700)	(900)
Dividend distribution to noncontrolling interests	0		0	(100)
Other financing activities	0		0	(200)
Net Cash Provided By Financing Activities	275,200		7,700	400
Effect of exchange rate changes on cash and cash equivalents	7,200		(2,100)	(7,800)
Net (decrease) increase in cash, cash equivalents, restricted cash, and restricted cash equivalents	(150,600)		158,300	20,100
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	282,000		123,700	103,600
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 131,400	[1]	$ 282,000	$ 123,700

[1] (1) Refer to Note 7, Debt and Credit Arrangements and Note 10, Business Combinations for further information regarding restricted cash and restricted cash equivalents balances.