Business (Narratives) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Business and Basis of Presentation
Capital interest ownership in operating partnership	99.985%
Special general partners interest	0.015%
Proceeds from issuance, initial public offering	$ 582.4
Equity Distributions
Daily distributions	$ 0.0016304
Daily distributions, cash	$ 0.0013587
Daily distributions, shares	$ 0.0002717
Annualized dividend rate	$ 0.6000
Dividend payable date	2013-10
Subsequent Event
Equity Distributions
Follow-on offering, authorized amount	$ 350.0