Organization and Summary of Significant Accounting Policies, Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	[1]	$ 57,308	$ 71,346
Current-period other comprehensive gain (loss)	[1]	221	(27)
Balances	[1]	56,458	57,308
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances		(2,329)	(2,302)
Current-period other comprehensive gain (loss)		221	(27)
Balances		(2,108)	(2,329)
Foreign Currency Translation Losses [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances		(2,288)
Current-period other comprehensive gain (loss)		264
Balances		(2,024)	(2,288)
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances		(41)
Current-period other comprehensive gain (loss)		(43)
Balances		$ (84)	$ (41)

[1] Prior periods adjusted to reflect the impact of the one-for-three reverse stock split that became effective on January 20, 2017, as discussed in Note 1.