Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 14,616	$ 16,368	$ 28,653	$ 30,745
Basic EPS, Shares	83,294	83,248	83,293	83,308
Basic EPS, Per Share Amount	$ 0.18	$ 0.20	$ 0.34	$ 0.37
Effect of restricted stock	$ 0	$ 0	$ 0	$ 0
Effect of restricted stock, Shares	44	71	44	82
Diluted EPS, Net Income	$ 14,616	$ 16,368	$ 28,653	$ 30,745
Diluted EPS, Shares	83,338	83,319	83,337	83,390
Diluted EPS, Per Share Amount	$ 0.18	$ 0.20	$ 0.34	$ 0.37