CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income (loss)		$ (39,265)	$ (663,925)	$ 11,946
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Benefit of deferred income taxes		(6,566)	(2,875)	(24,555)
Depreciation and amortization		60,535	83,069	55,188
Provision for arbitration award			11,282
Impairment of assets		8,618	544,611
Non-cash interest on convertible notes				224
Provision for bad debts		1,552	3,766	8,699
Provision for inventory reserves and revaluation, net		11,053	21,550	2,334
Stock-based compensation		31,295	34,733	32,793
(Gain) loss on the disposition of property and equipment		2,529	(43)	(227)
Loss on conversion of convertible debt				1,806
Changes in operating accounts, net of acquisitions:
Accounts receivable		27,130	20,890	(55,977)
Inventories		(22,178)	(31,241)	(33,088)
Prepaid expenses and other current assets		(4,369)	2,197	(9,235)
Accounts payable		(5,878)	(18,904)	23,482
Accrued and other current liabilities		(6,652)	624	15,406
All other operating activities		(902)	(8,862)	22,315
Net cash provided by (used in) operating activities		56,902	(3,128)	51,111
Cash flows from investing activities:
Purchases of property and equipment		(16,567)	(22,399)	(22,727)
Additions to license and patent costs		(1,132)	(907)	(753)
Proceeds from disposition of property and equipment		350
Purchase of noncontrolling interest		(3,533)
Cash paid for acquisitions, net of cash assumed			(91,799)	(345,361)
Other investing activities		(1,000)	(5,750)	(6,600)
Net cash used in investing activities		(21,882)	(120,855)	(375,441)
Cash flows from financing activities:
Tax benefits (provision) from share-based payment arrangements			(1,243)	7,653
Proceeds from issuance of common stock				299,729
Proceeds, repurchase and retirement of stock, net		(2,871)	135	1,896
Repayment of capital lease obligations		(1,055)	(1,049)	(696)
Net cash provided by (used in) financing activities		(3,926)	(2,157)	308,582
Effect of exchange rate changes on cash and cash equivalents		(1,790)	(3,079)	(5,706)
Net increase (decrease) in cash and cash equivalents		29,304	(129,219)	(21,454)
Cash and cash equivalents at the beginning of the period		155,643	284,862	306,316
Cash and cash equivalents at the end of the period		184,947	155,643	284,862
Supplemental Cash Flow Information:
Cash interest payments		839	707	888
Cash income tax payments		11,045	12,512	15,602
Transfer of equipment from inventory to property and equipment, net	[1]	12,493	9,902	5,891
Transfer of equipment to inventory from property and equipment, net	[2]	$ 1,102	$ 2,764	944
Stock issued for acquisitions of businesses				24,625
Notes redeemed for shares of common stock				$ 12,134

[1] Inventory is transferred from inventory to property and equipment at cost when the Company requires additional machines for training or demonstration or for placement into on-demand parts services locations.

[2] In general, an asset is transferred from property and equipment, net into inventory at its net book value when the Company has identified a potential sale for a used machine.