Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities
Net income (loss)	$ (27,496)	$ 3,949
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	21,725	11,600
Deferred income taxes	879	(2,675)
Asset impairment	126
Share-based compensation expense	8,919	9,813
Provision of bad debts		(1,936)
Gain on sale of lab tools	(179)	(2,435)
Change in contingent consideration		(29,368)
Changes in operating assets and liabilities:
Accounts receivable	(22,709)	(32,721)
Inventory and deferred cost of sales	(21,269)	7,062
Prepaid expenses and other current assets	(2,844)	(1,631)
Accounts payable and accrued expenses	19,041	(1,214)
Customer deposits and deferred revenue	31,599	22,826
Income taxes receivable and payable, net	2,309	646
Other, net	1,860	(692)
Net cash provided by (used in) operating activities	11,961	(16,776)
Cash Flows from Investing Activities
Capital expenditures	(7,530)	(4,509)
Proceeds from the liquidation of short-term investments	50,147	121,233
Payments for purchases of short-term investments	(11,998)	(92,029)
Proceeds from sale of lab tools	1,533	7,034
Other	(865)	(685)
Net cash provided by investing activities	31,287	31,044
Cash Flows from Financing Activities
Proceeds from stock option exercises	1,157	9,125
Payments of tax withholdings - restricted shares	(1,180)	(1,867)
Repayments of long-term debt	(153)	(141)
Net cash provided by (used in) financing activities	(176)	7,117
Effect of exchange rate changes on cash and cash equivalents	(30)	148
Net increase in cash and cash equivalents	43,042	21,533
Cash and cash equivalents - beginning of period	270,811	210,799
Cash and cash equivalents - end of period	313,853	232,332
Supplemental information:
Interest paid	71	82
Income taxes paid	$ 2,625	$ 1,999