Equity And Accumulated Other Comprehensive Income, Net (Equity Distribution Agreements) (Narrative) (Details) (2011 Equity Distribution Agreements, USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Jun. 29, 2011
2011 Equity Distribution Agreements
Equity and Accumulated Other Comprehensive Income (Loss) [Line Items]
Aggregate offering price of the distribution agreement maximum		$ 400,000,000
Net proceeds from sale of common stock	342,700,000
Issuance of common shares (shares)	5.7
Equity distribution agreements at an average price ($ per share)	$ 60.35
Payment of commissions to sales agents	3,500,000
Aggregate offering price remaining available for offer and sale	$ 53,800,000