Investments in Affiliated Companies (Summarized Financial Data-RRPF) (Details 6) $ in Millions		12 Months Ended
		Dec. 31, 2016 USD ($) AircraftEngines	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		$ 2,641.7	$ 2,505.6
Income Statement [Abstract]
Lease revenue		333.7	339.3	$ 339.0
Income taxes		(7.8)	(15.4)
Net income		99.3	121.4	99.6
Assets [Abstract]
Current assets		254.1	185.0
Other noncurrent assets		3,363.6	3,254.1
Total assets		3,617.7	3,439.1
Liabilities and Equity [Abstract]
Current liabilities		551.0	285.5
Long-term debt		2,341.4	2,512.2
Shareholders’ equity		725.3	641.4
Total liabilities and shareholders' equity		3,617.7	3,439.1
RRPF Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		$ 1,007.4	993.6
Number of Aircraft Engines | AircraftEngines		407
Income Statement [Abstract]
Depreciation expense		$ (171.6)	(166.1)	(140.7)
Interest expense		(59.2)	(56.7)	(59.5)
Other expenses		(8.0)	(8.8)	(11.8)
Gains on sales of assets		19.1	33.1	22.7
Income before income taxes		104.2	131.6	112.3
Income taxes	[1]	(6.9)	(9.0)	(17.3)
Net income		97.3	122.6	95.0
Assets [Abstract]
Current assets		241.3	173.4
Operating assets, net of accumulated depreciation of $744.5 and $651.8	[2]	3,281.9	3,161.4
Total assets		3,523.2	3,334.8
Liabilities and Equity [Abstract]
Current liabilities		127.3	85.1
Long-term debt		2,452.9	2,391.1
Other liabilities		233.8	231.4
Shareholders’ equity		709.2	627.2
Total liabilities and shareholders' equity		3,523.2	3,334.8
RRPF Joint Ventures [Member] | Third Parties [Member]
Income Statement [Abstract]
Lease revenue		173.7	191.4	176.9
RRPF Joint Ventures [Member] | Rolls-Royce [Member]
Income Statement [Abstract]
Lease revenue		$ 150.2	$ 138.7	$ 124.7

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