Consolidated Statements of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING ACTIVITIES:
Net (loss) income	$ (3,446,000)	$ 3,991,000
Adjustments to reconcile net (loss) income to net cash (used for) provided by operating activities:
Depreciation, amortization and other	6,123,000	6,202,000
Stock-based compensation expense	1,980,000	2,068,000
Amortization of debt discount and deferred issuance costs	1,429,000	1,399,000
Change in deferred tax assets and liabilities	(2,629,000)	1,285,000
Change in fair value of acquisition contingencies	0
Gain on extinguishment of debt	(421,000)
Changes in assets and liabilities:
Accounts receivable	(7,719,000)	15,782,000
Inventories	2,136,000	786,000
Income taxes receivable	119,000	372,000
Prepaid expenses and other current and non-current assets	(1,186,000)	(457,000)
Restricted cash	63,000	(338,000)
Accounts payable	1,150,000	(3,196,000)
Accrued payroll and related expenses	(3,290,000)	(870,000)
Income taxes payable	(167,000)	(2,000)
Deferred grant revenue	(1,746,000)	(1,212,000)
Other current and non-current liabilities	7,000	5,956,000
Net cash (used for) provided by operating activities:	(7,597,000)	31,766,000
INVESTING ACTIVITIES:
Acquisitions of property, equipment and intangibles	(2,001,000)	(2,867,000)
Payments to Acquire Businesses, Net of Cash Acquired	5,094,000
Net cash used for investing activities:	(7,095,000)	(2,867,000)
FINANCING ACTIVITIES:
Payments on lease obligation	(141,000)	(121,000)
Repurchases of common stock	(20,079,000)	(337,000)
Repurchases of Convertible Senior Notes	(4,459,000)	0
Proceeds from issuance of common stock	1,554,000	596,000
Payments of debt issuance costs	0	(365,000)
Payments on acquisition contingencies	(195,000)	(129,000)
Net cash used for financing activities	(23,320,000)	(356,000)
Effect of exchange rates on cash	(12,000)	(9,000)
Net (decrease) increase in cash and cash equivalents	(38,024,000)	28,534,000
Cash and cash equivalents, beginning of period	191,471,000
Cash and cash equivalents, end of period	153,447,000
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest Paid	279,000	250,000
Income Taxes Paid	103,000	121,000
NON-CASH INVESTING ACTIVITIES:
Noncash or Part Noncash Acquisition, Fixed Assets Acquired	1,269,000	164,000
NON-CASH FINANCING ACTIVITIES:
Reduction Of Other Current Liabilities Upon Issuance Of Restricted Share Units	539,000	$ 408,000
Senior 3 Point 25 Percent Convertible Notes Due 2020 [Member] | Convertible Debt [Member]
Adjustments to reconcile net (loss) income to net cash (used for) provided by operating activities:
Gain on extinguishment of debt	(421,000)
FINANCING ACTIVITIES:
Repurchases of Convertible Senior Notes	$ (4,500,000)