CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating Activities
Net income	$ 72,004	$ 94,163
Adjustments to reconcile net income to cash provided by operations:
Depreciation and amortization	25,229	16,232
Stock-based compensation expense	5,692	5,510
Loss on disposal of property, plant and equipment	153	18
Changes in operating assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	(96,481)	(23,844)
Inventories	(32,145)	1,400
Accounts payable	(24,690)	(18,002)
Accrued income taxes	2,188	29,779
Accrued liabilities and customer deposits	85,303	(12,832)
Other assets and liabilities	(63,349)	(16,858)
Net cash (used for) provided by operating activities	(26,096)	75,566
Investing Activities
Purchase of property, plant and equipment	(19,327)	(8,504)
Proceeds from disposal of property, plant and equipment	284	84
Acquisitions of businesses, net of cash acquired	(67,581)	(210)
Release of deposit in escrow	23,548	0
Net cash used for investing activities	(63,076)	(8,630)
Financing Activities
Proceeds from debt	458,273	195,000
Payments of debt	(482,591)	(85,453)
Purchase of treasury stock	0	(133,738)
Proceeds from exercise of stock options and other benefit plans	1,259	515
Payment of income tax withholding on share-based compensation	(6,842)	(9,006)
Cash dividends ($0.10 and $0.08 per share for the three months ended March 31, 2017 and 2016, respectively)	(9,572)	(7,355)
Net cash used for financing activities	(39,473)	(40,037)
Effect of changes in currency exchange rates	10,340	9,684
(Decrease) Increase in cash	(118,305)	36,583
Cash, beginning of period	398,484	226,191
Cash, end of period	$ 280,179	$ 262,774