Supplemental Cash Flow and Noncash Investing Transactions (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended							3 Months Ended
	Dec. 31, 2013 Car	Dec. 31, 2012 Vessel	Dec. 31, 2011 Vessel	Dec. 31, 2013 Singco/Somagas [Member]	Dec. 31, 2013 Aae Cargo Ag [Member]	Dec. 31, 2012 Aae Cargo Ag [Member]	Dec. 31, 2011 Aae Cargo Ag [Member]	Dec. 31, 2013 Aae Cargo Ag [Member]	Mar. 31, 2013 Aae Cargo Ag [Member]
Noncash or Part Noncash Divestitures [Line Items]
Portfolio proceeds	$ 385.3	$ 288.9	$ 154.1		$ 91.1	$ 0	$ 0	$ 91.1	$ 91.1
Supplemental Cash Flow and Noncash Investing and Financing Transactions (Textual) [Abstract]
Aggregate fair value of liquidating distributions	$ 22.9		$ 88.8	$ 151.8
Number of railcars received	640
Number of vessels containing liquidating distributions		6	6