Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Equity [Abstract]
Stock repurchased (in shares)				6,205,046
Common stock issued under stock compensation plan (in shares)				2,458,048
Net decrease in period (in shares)				3,746,998
Increase in quarterly cash dividend rate (in dollars per share)	$ 0.005
Dividends declared (in dollars per share)	$ 0.09	$ 0.085	$ 0.085	$ 0.175	$ 0.165
Dividends declared	$ 25.9