Certain Financial Statement Information Interest Income/Expense (Details) (USD $)	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Schedule of Interest Income, Net
Interest income	$ 341,000	$ 468,000
Net realized (loss) gain on short-term investments	0	3,200,000
Interest income, net	$ 336,000	$ 3,666,000