Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended	12 Months Ended	18 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Jul. 31, 2016
Equity [Abstract]
Maximum stock repurchase program amount				$ 200,000,000
Stock repurchased during period (in Shares)	0.0	1.8	1.8
Average price per share of stock repurchased (in Dollars per share)		$ 24.89	$ 24.89
Remaining repurchase authorization	$ 155,000,000		$ 155,000,000