Significant Accounting Policies, Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance				$ (17,747)
Net current period other comprehensive loss		$ (41)	$ 13	(63)	$ 83
Ending balance		(82,983)		(82,983)
Tax benefit included in other comprehensive loss		0		0
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance		(43)	(5)	(21)	(75)
Ending balance		(84)	8	(84)	8
Unrealized Losses on Securities [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Other comprehensive loss before reclassifications, net of tax	[1]	1	13	(27)	83
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Loss [Roll Forward]
Other comprehensive loss before reclassifications, net of tax		$ (42)	$ 0	$ (36)	$ 0

[1] There was no tax benefit for other comprehensive loss for the three and six months ended June 30, 2017 and 2016.