Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Income (Loss) from Continuing Operations Attributable to Parent	$ 152.6	$ (70.8)	$ 146.8
Numerator:
Less: undistributed earnings allocated to nonvested stock	$ 0.0	$ 0.0	$ 0.0
Income (Loss) from Continuing Operations, Per Basic and Diluted Share	$ 152,600,000	$ (70,800,000)	$ 146,800,000
Denominator:
Weighted-average number of shares outstanding - basic	78,516,029	84,631,778	90,367,345
Effect of dilutive securities:
Stock options and awards - based on the treasury stock method (in shares)	718,295	0	856,983
Weighted-average number of shares outstanding, assuming dilution of stock options and awards	79,234,324	84,631,778	91,224,328
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.94	$ (0.84)	$ 1.62
Income (Loss) from Continuing Operations, Per Diluted Share	$ 1.92	$ (0.84)	$ 1.61