7. Shareholders' Equity (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Repurchase of common stock, value	$ (10,468)	$ (5,926)
Weighted average exercise price of stock options granted	$ 1.38	$ 2.41	$ 2.73
Voliatility assumptions, minimum	44.00%	47.00%	52.00%
Voliatility assumptions, maximum	51.00%	51.00%	55.00%
Stock-based compensation	$ 5,553	$ 5,024	$ 3,835
Unrecognized stock-based compensation costs	$ 10,100
Weighted-average period for unrecognized costs	2 years 1 month 6 days
Intrinsic value options outstanding	$ 17,800	16,600
Intrinsic value of options exercisable	14,200	14,500
Intrinsic value of options exercised	1,300	$ 6,400
Proceeds from options exercised	633
Tax benefit from options exercised	$ 73
Shares available for grant	3,700,000
Warrants outstanding	2,000,000
Common Stock | Authorizations prior to December 31, 2015 [Member]
Amount remaining of stock repurchase authorized amount	$ 5,100
Common Stock | No expiration [Member]
Amount remaining of stock repurchase authorized amount	$ 4,700
Common Stock
Repurchase of common stock, shares	2,477,453
Common Stock | Open Market [Member]
Repurchase of common stock, shares	2,453,706
Repurchase of common stock, value	$ 10,400
Common Stock | Net exercises of outstanding options and warrants [Member]
Repurchase of common stock, shares	23,747