Shareholders' Equity - Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		12 Months Ended	0 Months Ended
	Jan. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Mar. 25, 2014
Class of Stock [Line Items]
Distributions declared per common share (in dollars per share)	$ 0.25	$ 0	$ 0.25
Distributions paid or declared on common shares	$ 29.6
Common Shares
Class of Stock [Line Items]
Common shares issued to holders of preferred shares (in shares)		144		10,412,499
Common shares from conversion of preferred shares (in shares)		2,363,103
Series D
Class of Stock [Line Items]
Preferred shares converted into common shares (in shares)		301		10,264,503
Common shares from conversion of preferred shares (in shares)		4,915,196
Fundamental change conversion right | Common Shares
Class of Stock [Line Items]
Preferred shares converted into common shares (in shares)					10,411,779
Fundamental change conversion right | Series D
Class of Stock [Line Items]
Preferred shares converted into common shares (in shares)					10,263,003