Financial Statements for Guarantors of the Senior Notes (Details Textual) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Restricted cash	$ 211.1	[1]	$ 234.7
Assets	8,722.4	[1]	8,733.8
Combined Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Restricted cash	174.0		194.4
Equipment securing certain non-recourse debt	3,856.6		3,936.8
Equipment securing certain lease obligations	71.3		87.5
Assets	5,511.7		5,607.9
Combined Non-Guarantor Subsidiaries | Foreign locations
Condensed Financial Statements, Captions [Line Items]
Assets	$ 370.1		$ 395.5

[1] (unaudited)