3. Fair Value Measurement (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets
Money market fund and trust cash sweep investments (1)	$ 0	$ 4,367
Total Assets	0	4,367
Level 1 Member
Assets
Money market fund and trust cash sweep investments (1)	0	4,367
Total Assets	0	4,367
Level 2 Member
Assets
Money market fund and trust cash sweep investments (1)	0	0
Total Assets	0	0
Level 3 Member
Assets
Money market fund and trust cash sweep investments (1)	0	0
Total Assets	$ 0	$ 0