Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ (407,088)	$ (51,396)	$ (122,027)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	49,998	50,095	32,650
Non-cash interest expense	11,762	10,446
Deferred income taxes	(27,620)	(35,363)	997
Share-based compensation expense	16,074	24,396	15,741
Asset impairment	375,172	1,139	69,520
Provision for bad debts		99	171
Gain on cumulative translation adjustment			(430)
Changes in operating assets and liabilities:
Accounts receivable and contract assets	21,821	10,240	(8,880)
Inventories and deferred cost of sales	(24,678)	6,244	(6,106)
Prepaid expenses and other current assets	11,216	(10,204)	6,726
Accounts payable and accrued expenses	(19,672)	11,308	(24,474)
Customer deposits and deferred revenue	(39,296)	22,446	9,770
Income taxes receivable and payable, net	(4,800)	775	547
Long-term income tax liability		(4,877)
Other, net	(627)	(355)	1,951
Net cash provided by (used in) operating activities	(37,738)	34,993	(23,844)
Cash Flows from Investing Activities
Acquisitions of businesses, net of cash acquired	(2,662)	(401,828)
Capital expenditures	(12,654)	(24,272)	(11,479)
Proceeds from the sale of investments	90,065	348,927	152,301
Payments for purchases of investments	(93,046)	(282,947)	(103,394)
Proceeds from held for sale assets		2,284	9,512
Other			(230)
Net cash provided by (used in) investing activities	(18,297)	(357,836)	46,710
Cash Flows from Financing Activities
Proceeds (net of tax withholdings) from option exercises and employee stock purchase plan	3,064	2,992	1,656
Restricted stock tax withholdings	(3,069)	(8,741)	(2,601)
Purchases of common stock	(11,457)	(2,869)	(13,349)
Proceeds from long-term debt borrowings		335,752
Principal payments on long-term debt		(1,194)	(340)
Net cash provided by (used in) financing activities	(11,462)	325,940	(14,634)
Effect of exchange rate changes on cash and cash equivalents	(4)	42	(20)
Net increase (decrease) in cash, cash equivalents, and restricted cash	(67,501)	3,139	8,212
Cash, cash equivalents, and restricted cash - beginning of period	280,583	277,444	269,232
Cash, cash equivalents, and restricted cash - end of period	213,082	280,583	277,444
Supplemental Disclosure of Cash Flow Information
Interest paid	9,708	4,675	225
Income taxes paid	4,799	1,939	1,669
Non-cash operating and financing activities
Net transfer of inventory to property, plant and equipment	$ 1,479	$ (97)	$ 1,827