Significant Accounting Policies, Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ 99,565
Net current period other comprehensive loss		(102)	$ (2,550)
Ending balance		201,806
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(30,358)	(13,565)
Ending balance		(30,460)	(16,115)
Unrealized Losses on Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive loss before reclassifications, net of tax	[1]	266	(2,550)
Amounts reclassified from accumulated other comprehensive income	[2]	(374)	0
Income tax benefit included in other comprehensive loss		0	0
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Other comprehensive loss before reclassifications, net of tax		$ 6	$ 0

[1] There was no tax benefit for other comprehensive loss for the three months ended March 31, 2017 and 2016.

[2] Amounts are included in investment income on our condensed consolidated statement of operations.