Equity (Narrative) (Details) - shares	3 Months Ended
	Mar. 31, 2016	Dec. 04, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest in joint venture minimum percentage (at least)	20.00%
Agreement terms, change of control, put option for minority interest ownership, effective period	15 days
2013 Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for repurchase		50,000,000
Maximum number of shares authorized for repurchase, as percentage of outstanding common stock		18.00%
Remaining shares available under repurchase program (in shares)	33,300,000