Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 7,916	$ 12,527	$ 36,568	$ 43,272
Basic EPS, Shares	83,303	83,286	83,296	83,301
Basic EPS, Per Share Amount	$ 0.10	$ 0.15	$ 0.44	$ 0.52
Effect of restricted stock	$ 0	$ 0	$ 0	$ 0
Effect of restricted stock, Shares	30	56	40	72
Diluted EPS, Net Income	$ 7,916	$ 12,527	$ 36,568	$ 43,272
Diluted EPS, Shares	83,333	83,342	83,336	83,373
Diluted EPS, Per Share Amount	$ 0.09	$ 0.15	$ 0.44	$ 0.52