Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Shareholders' Equity [Abstract]
Common stock repurchased during the period (in shares)	89,251	600,000	400,477	2,500,000
Common stock repurchased during the period, value	$ 6.7	$ 38.2	$ 25.2	$ 165.4