CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 170,728	$ 144,164
Adjustments to reconcile net income to cash provided by operations:
Depreciation and amortization	53,227	51,051
Stock-based compensation expense	13,983	11,879
Loss on disposal of property, plant and equipment	1,353	525
Changes in operating assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	(59,979)	(66,544)
Inventories	(116,131)	(48,406)
Accounts payable	59,411	(75,761)
Accrued income taxes	(202)	(23,025)
Accrued liabilities and customer deposits	27,545	86,937
Other assets and liabilities	(82,031)	(94,523)
Net cash provided by (used for) operating activities	67,904	(13,703)
Investing Activities
Purchase of property, plant and equipment	(39,723)	(38,425)
Proceeds from disposal of property, plant and equipment	8,900	471
Acquisitions of businesses, net of cash acquired	(38,277)	(846,675)
Net cash used for investing activities	(69,100)	(884,629)
Financing Activities
Proceeds from debt	591,890	745,035
Payments of debt	(546,394)	(680,145)
Proceeds from exercise of stock options and other benefit plans	6,867	2,679
Payment of income tax withholding on share-based compensation	(6,503)	(6,802)
Cash dividends ($0.12 and $0.20 per share for the six months ended June 30, 2018 and 2017, respectively)	(23,096)	(19,177)
Net cash provided by financing activities	22,764	41,590
Effect of changes in currency exchange rates	(9,395)	42,032
Increase (Decrease) in cash	12,173	(814,710)
Cash, cash equivalents and restricted cash, beginning of period	233,401	1,143,232
Cash and cash equivalents, end of period	$ 245,574	$ 328,522