Debt (Details Textual)	6 Months Ended	12 Months Ended
Jun. 30, 2016 USD ($) day $ / shares	Dec. 31, 2015 USD ($)
Corporate \| Convertible subordinated notes \| 3 7/8% Convertible Subordinated Notes Due 2036 [Member]
Debt Instrument [Line Items]
Capital in excess of par value related to the Convertible Subordinated Notes' conversion options	$ 92,500,000	$ 92,500,000
Effective annual interest rate yield	8.42%
Percentage of conversion price at which Convertible Subordinated Notes are convertible (greater than or equal to)	130.00%
Convertible debt, trading days threshold \| day	20
Convertible debt, consecutive trading days threshold	30 days
Conversion price of convertible subordinated notes (in dollars per share) \| $ / shares	$ 24.75
Corporate \| Revolving credit facility \| Line of credit
Debt Instrument [Line Items]
Revolving credit facility	$ 600,000,000
Line of Credit Facility, Remaining Borrowing Capacity	507,400,000
Borrowing under revolving credit facility exclusive of letters of credit	0
Corporate \| Letter of credit \| Line of credit
Debt Instrument [Line Items]
Used revolving credit facility for letters of credit	92,600,000
Letters of credit expiring in current year	4,500,000
Railcar Leasing and Management Services Group \| Revolving credit facility \| Line of credit \| TILC warehouse facility \| TILC [Member]
Debt Instrument [Line Items]
Revolving credit facility	$ 1,000,000,000.0
Effective annual interest rate yield	2.35%
TILC warehouse loan, amount outstanding	$ 240,500,000
Railcar Leasing and Management Services Group \| Revolving credit facility \| Line of credit \| TILC warehouse facility \| Wholly-owned subsidiaries
Debt Instrument [Line Items]
TILC warehouse loan, unused portion	$ 759,500,000

Letters Of Credit Outstanding Expiring In Current Fiscal Year

No definition available.

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- Definition

Line of Credit Facility, Amount Outstanding Exclusive of Letters of Credit

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Line of Credit Facility, Remaining Borrowing Capacity Exclusive of Current Restrictions

+ References

No definition available.

+ Details

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- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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- Definition

Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

+ References

No definition available.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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