Investments in Affiliated Companies (Summarized Financial Data-RRPF) (Details 6) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Statement [Abstract]
Lease revenue	$ 339.0		$ 334.5		$ 651.8
Income taxes			(15.2)		(9.2)
Net income	99.6		108.6		75.3
Assets [Abstract]
Current assets	211.6		200.5
Other noncurrent assets	3,195.1		2,989.2
Total assets	3,406.7		3,189.7
Liabilities and Equity [Abstract]
Current liabilities	378.4		159.6
Long-term debt	2,388.2		2,408.8
Shareholders’ equity	640.1		621.3
Total liabilities and shareholders' equity	3,406.7		3,189.7
RRPF Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
number of aircraft engines	433
Income Statement [Abstract]
Depreciation expense	(140.7)		(120.2)		(115.1)
Interest expense	(59.5)		(65.8)		(64.8)
Other expenses	(11.8)		(10.2)		(16.3)
Gains on sales of assets	22.7		35.2		35.9
Income before income taxes	112.3		106.3		93.0
Income taxes	(17.3)	[1]	0.4	[1]	(3.8)	[1]
Net income	95.0		106.7		89.2
Assets [Abstract]
Current assets	146.3		151.0
Operating assets, net of accumulated depreciation of $744.5 and $651.8	2,988.1	[2]	2,619.6	[2]
Total assets	3,134.4		2,770.6
Liabilities and Equity [Abstract]
Current liabilities	358.5		141.0
Long-term debt	2,012.9		1,963.1
Other liabilities	218.1		212.4
Shareholders’ equity	544.9		454.1
Total liabilities and shareholders' equity	3,134.4		2,770.6
RRPF Joint Ventures [Member] | Third Parties [Member]
Income Statement [Abstract]
Lease revenue	176.9		147.6		140.4
RRPF Joint Ventures [Member] | Rolls-Royce [Member]
Income Statement [Abstract]
Lease revenue	$ 124.7		$ 119.7		$ 112.9

[1] (1) Represents income taxes directly attributable to the RRPF affiliates in the United Kingdom. Several of the RRPF affiliates are flow through entities and income taxes are incurred at the shareholder level. Amounts shown for 2013 and 2012 include tax benefits of approximately $15.2 million and $9.2 million, attributable to statutory rate decreases in the United Kingdom.

[2] (a) All operating assets were pledged as collateral for long-term debt obligations.