Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	[1]	Jun. 30, 2016	Jun. 30, 2015	[1]
Statement of Comprehensive Income [Abstract]
Net income	$ 8,522	$ 8,902		$ 519	$ 3,074
Unrealized gains (losses) on marketable securities, net of tax	20	(17)		54	27
Comprehensive income	$ 8,542	$ 8,885		$ 573	$ 3,101

[1] See Note 2. Restatement of Previously Issued Condensed Consolidated Financial Statements