Equity (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended			6 Months Ended
	May. 21, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Equity [Abstract]
Stock repurchased (in shares)		1,427,469			2,834,064
Common stock issued under stock compensation plan (in shares)					1,188,583
Net decrease in period (in shares)					1,645,481
Increase in quarterly cash dividend rate (in dollars per share)		$ 0.005
Dividends declared (in dollars per share)		$ 0.085	$ 0.08	$ 0.08	$ 0.165	$ 0.15
Dividends declared	$ 25.0