Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended			0 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Aug. 29, 2014	Oct. 17, 2014 Subsequent Event [Member]
Class of Stock [Line Items]
Common stock issued under stock compensation plan (in shares)					1,164,518
Stock repurchased (in shares)					351,565
Net increase in period (in shares)					812,953
Increase in its quarterly cash dividend rate		$ 0.02
Dividends declared (in dollars per share)	$ 0.16	$ 0.16	$ 0.14	$ 0.14	$ 0.46	$ 0.42
Dividends payable							$ 23.4
Dividends paid								$ 23.4