Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Flows from Operating Activities
Net income (loss)	$ 1,095	$ (15,533)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	5,799	8,593
Non-cash interest expense	2,185
Deferred income taxes	(6,001)	465
Share-based compensation expense	4,186	4,388
Asset impairment	463
Provision for bad debts	92	160
Changes in operating assets and liabilities:
Accounts receivable	6,495	(6,958)
Inventories and deferred cost of sales	13,761	1,274
Prepaid expenses and other current assets	(3,743)	(6,660)
Accounts payable and accrued expenses	642	(2,210)
Customer deposits and deferred revenue	(14,238)	(1,510)
Income taxes receivable and payable, net	130	(893)
Long-term income tax liability	(4,877)
Other, net	343	86
Net cash provided by (used in) operating activities	6,332	(18,798)
Cash Flows from Investing Activities
Capital expenditures	(4,187)	(3,988)
Proceeds from the sale of investments	27,411	10,930
Payments for purchases of investments	(219,141)
Other		(213)
Net cash provided by (used in) investing activities	(195,917)	6,729
Cash Flows from Financing Activities
Proceeds (tax withholdings) from stock option exercises and employee stock purchase plan	585	(22)
Restricted stock tax withholdings	(461)	(27)
Purchases of common stock		(13,349)
Proceeds from long-term debt borrowings	335,752
Principal payments of long-term debt	(89)	(82)
Net cash provided by (used in) financing activities	335,787	(13,480)
Effect of exchange rate changes on cash and cash equivalents	15	39
Net increase in cash and cash equivalents	146,217	(25,510)
Cash and cash equivalents - beginning of period	277,444	269,232
Cash and cash equivalents - end of period	423,661	243,722
Supplemental Disclosure of Cash Flow Information
Interest paid	31	39
Income taxes paid	672	$ 966
Non-cash operating and financing activities
Net transfer of inventory to property, plant and equipment	$ 81