Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019		Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income	$ 53,831		$ 35,929
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	37,838		35,908
Operatingleaserightofuseassetamortization	4,150		0
Provision for doubtful accounts	5,838		399
Provision for warranty and returns	1,249		513
Stock compensation	12,438		11,759
Loss on disposal of property and equipment	12,845		360
Bond premium amortization	68		204
Debt Issuance Costs amortization	144		144
Change in fair value of contingent earn-out	(47,200)		2,000
Asset Impairment Charges	0		269
Impairment of Intangible Assets, Finite-lived	0		5,000
Sparepartsusage	14,649		4,785
Other Noncash Income (Expense)	(346)		2,167
Cash provided by (used in) changes in operating assets and liabilities
Accounts receivable	(46,861)		(43,260)
Inventories	(16,060)		12,124
Prepaid expenses and other assets	6,111		4,414
Related-party receivables	0		24,143
Increase (Decrease) in Other Operating Assets	(18,079)		(5,705)
Accounts payable	2,032		17,459
Accrued liabilities	(21,124)		(36,387)
Income taxes, including excess tax benefits and deferred income taxes	735		(13,268)
Net cash provided by operating activities	2,258		58,957
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(48,726)		(47,365)
Proceeds from Sale of Other Productive Assets	0		13,000
Proceeds from sale of asset	19		0
Payments to Acquire Businesses, Net of Cash Acquired	4,600		1,300
Intangible assets additions	(4,088)		(4,047)
Purchases of investment securities	(17,994)		(8,480)
Proceeds from sale of investment securities	33,400		8,900
Net cash used in investing activities	(41,989)		(39,292)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	3,934		12,536
Payments Related to Tax Withholding for Share-based Compensation	18,265		5,469
Net cash (used in) provided by financing activities	(14,331)		7,067
Effect of exchange rate changes on cash	1,148		(7,707)
NET INCREASE DECREASE IN CASH AND CASH EQUIVALENTS	(52,914)		19,025
CASH AND CASH EQUIVALENTS, beginning of period	344,781	[1]	290,072
CASH AND CASH EQUIVALENTS, end of period	291,867
NON-CASH INVESTING ACTIVITIES
Capital Expenditures Incurred but Not yet Paid	$ 11,736		$ 2,508

[1] December 31, 2018 balances were derived from audited consolidated financial statements.