Partially-Owned Leasing Subsidiary	3 Months Ended
Mar. 31, 2013
Partially-Owned Leasing Subsidiary [Abstract]
Partially-Owned Leasing Subsidiary	Partially-Owned Leasing Subsidiary In 2007, the Company, through its wholly-owned subsidiary, and other third-party equity investors formed TRIP Holdings for the purpose of providing railcar leasing and management services in North America. TRIP Holdings, through its wholly-owned subsidiaries, purchased railcars from the Company’s Rail and Leasing Groups funded by capital contributions from TRIP Holdings’ equity investors and borrowings under the TRIP Holdings' credit facilities. As of March 31, 2013, TRIP Holdings’ subsidiaries had purchased $1,331.4 million of railcars from the Company. Railcars purchased from the Company by TRIP Holdings’ subsidiaries are required to be purchased at prices comparable with the prices of all similar, new railcars sold contemporaneously by the Company and at prices based on third-party appraised values for used railcars. See Note 11 Debt regarding TRIP Holdings and its related debt. The assets of TRIP Holdings may only be used to satisfy the liabilities of TRIP Holdings, and the liabilities and indebtedness of TRIP Holdings have recourse only to TRIP Holdings' assets. Effective March 2013, the Company purchased an additional 16% interest in TRIP Holdings from another equity investor for $31.7 million resulting in a reduction in the carrying amount of noncontrolling interest by $32.3 million. The transaction was cash settled in April 2013. Certain previous put/call agreements with the equity investor regarding their equity interest were terminated. At March 31, 2013, the Company owned 73% of TRIP Holdings with the remainder owned by two third-party equity investors. The Company's noncontrolling interest represents the non-Trinity equity interest in TRIP Holdings. The Company receives distributions from TRIP Holdings as an equity investor, when allowed, in proportion to its 73% equity interest, and has an interest in the net assets of TRIP Holdings upon a liquidation event in the same proportion. The terms of the Company’s equity investment are identical to the terms of each of the other equity investors. The manager of TRIP Holdings, TILC, may be removed without cause as a result of a majority vote of the third-party equity investors. Other than as described above, Trinity had no remaining equity commitment to TRIP Holdings as of March 31, 2013 and had no obligation to guarantee performance under any TRIP-related debt agreements, guarantee any railcar residual values, shield any parties from losses, or guarantee minimum yields. The Company’s carrying value of TILC's investment in TRIP Holdings, which is eliminated in consolidation, was $128.3 million and $95.6 million at March 31, 2013 and December 31, 2012, respectively. Administrative fees paid to TILC by TRIP Holdings and subsidiaries for the three month periods ended March 31, 2013 and 2012 were $1.3 million and $1.3 million, respectively.

Partially-Owned Leasing Subsidiary

In 2007, the Company, through its wholly-owned subsidiary, and other third-party equity investors formed TRIP Holdings for the purpose of providing railcar leasing and management services in North America. TRIP Holdings, through its wholly-owned subsidiaries, purchased railcars from the Company’s Rail and Leasing Groups funded by capital contributions from TRIP Holdings’ equity investors and borrowings under the TRIP Holdings' credit facilities. As of March 31, 2013, TRIP Holdings’ subsidiaries had purchased $1,331.4 million of railcars from the Company. Railcars purchased from the Company by TRIP Holdings’ subsidiaries are required to be purchased at prices comparable with the prices of all similar, new railcars sold contemporaneously by the Company and at prices based on third-party appraised values for used railcars. See Note 11 Debt regarding TRIP Holdings and its related debt. The assets of TRIP Holdings may only be used to satisfy the liabilities of TRIP Holdings, and the liabilities and indebtedness of TRIP Holdings have recourse only to TRIP Holdings' assets.

Effective March 2013, the Company purchased an additional 16% interest in TRIP Holdings from another equity investor for $31.7 million resulting in a reduction in the carrying amount of noncontrolling interest by $32.3 million. The transaction was cash settled in April 2013. Certain previous put/call agreements with the equity investor regarding their equity interest were terminated.

At March 31, 2013, the Company owned 73% of TRIP Holdings with the remainder owned by two third-party equity investors. The Company's noncontrolling interest represents the non-Trinity equity interest in TRIP Holdings. The Company receives distributions from TRIP Holdings as an equity investor, when allowed, in proportion to its 73% equity interest, and has an interest in the net assets of TRIP Holdings upon a liquidation event in the same proportion. The terms of the Company’s equity investment are identical to the terms of each of the other equity investors. The manager of TRIP Holdings, TILC, may be removed without cause as a result of a majority vote of the third-party equity investors. Other than as described above, Trinity had no remaining equity commitment to TRIP Holdings as of March 31, 2013 and had no obligation to guarantee performance under any TRIP-related debt agreements, guarantee any railcar residual values, shield any parties from losses, or guarantee minimum yields.

The Company’s carrying value of TILC's investment in TRIP Holdings, which is eliminated in consolidation, was $128.3 million and $95.6 million at March 31, 2013 and December 31, 2012, respectively.

Administrative fees paid to TILC by TRIP Holdings and subsidiaries for the three month periods ended March 31, 2013 and 2012 were $1.3 million and $1.3 million, respectively.