Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Reconciliation of the component parts of earnings per share [Abstract]
Net income	$ 11,254	$ 13,313	$ 14,667	$ 14,558	$ 24,567	$ 29,225
Weighted average common shares (in shares)	96,433		96,822		96,580	96,784
Stock Options (in shares)	4		69		13	73
Weighted average common shares including potential dilutive shares (in shares)	96,437		96,891		96,593	96,857
Basic EPS (in dollars per share)	$ 0.117		$ 0.152		$ 0.254	$ 0.302
Diluted EPS (in dollars per share)	$ 0.117		$ 0.151		$ 0.254	$ 0.302
Stock Options [Member]
Antidilutive Securities [Abstract]
Number of antidilutive stock options excluded from diluted earnings per share (in shares)	452		0		452	0