CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Investments measured at fair value	$ 25,071	$ 22,590
Liabilities and shareholders’ equity
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	23,125,000	23,116,000
Common stock, shares outstanding (in shares)	23,070,000	23,038,000
Treasury stock, common shares held (in shares)	55,000	78,000