Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 23,316	$ 26,472	$ 40,928	$ 40,551
Basic EPS, Shares	87,814	87,728	87,802	87,716
Basic EPS, Per Share Amount	$ 0.27	$ 0.30	$ 0.47	$ 0.46
Effect of restricted stock	$ 0	$ 0	$ 0	$ 0
Effect of restricted stock, Shares	153	172	164	192
Diluted EPS, Net Income	$ 23,316	$ 26,472	$ 40,928	$ 40,551
Diluted EPS, Shares	87,967	87,900	87,966	87,908
Diluted EPS, Per Share Amount	$ 0.27	$ 0.30	$ 0.47	$ 0.46