Condensed Consolidated Statements of Comprehensive Loss (unaudited) - USD ($)		3 Months Ended
		Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net loss		$ (7,404,000)	$ (13,065,000)	[1]
Other comprehensive loss, net of tax:
Unrealized (loss) gain on investments	[2]	(1,653,000)	467,000
Loss on foreign currency translation		(137,000)	(88,000)
Other comprehensive (loss) gain, net of tax		(1,790,000)	379,000
Total comprehensive loss		(9,194,000)	(12,686,000)
Reclassification adjustment from AOCI to earnings, short term investments		$ (1,400,000)	$ 0

[1] The Statement of Cash Flows for the three months ended June 30, 2014 reflects an immaterial revision to correct outstanding payables related to purchases of property and equipment previously included in net cash used for investing activities to net cash used for operating activities. As a result, net cash used for operating activities increased by $0.3 million and net cash used for investing activities decreased by the corresponding amount.

[2] The amounts reclassified from accumulated other comprehensive loss and recorded in net realized gain on short-term investments and interest income, net in the Condensed Consolidated Statement of Operations relating to sale of short-term investments were $1.4 million and zero for the three months ended June 30, 2015 and 2014, respectively. Refer to Note 2, Certain Financial Statement Information, to the Condensed Consolidated Financial Statements for additional details.