Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Net income	$ 13,617	$ 12,888	$ 39,083	$ 36,456
Denominator:
Weighted average shares outstanding	70,299,722	70,129,056	70,228,127	70,071,999
Effect of dilutive securities (in shares)	151,038	110,964	166,338	135,984
Adjusted weighted average shares outstanding	70,450,760	70,240,020	70,394,465	70,207,983
EPS, Basic (in dollars per share)	$ 0.19	$ 0.18	$ 0.56	$ 0.52
EPS, Fully Diluted (in dollars per share)	$ 0.19	$ 0.18	$ 0.56	$ 0.52