Business Combinations Pro Forma Results of Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Business Acquisition, Pro Forma Information [Abstract]
Revenues	$ 281,182	$ 262,059
Net income	$ 16,195	$ 11,270
Basic net income per share	$ 0.51	$ 0.34
Diluted net income per share	$ 0.50	$ 0.33
Shares used in computing basic net income per share	31,554	32,973
Shares used in computing diluted net income per share	32,209	34,140