Partially-Owned Leasing Subsidiaries (Details Textual) - Jun. 30, 2015 - Leasing Group $ in Millions	USD ($) subsidiaries board_members
Partially-owned subsidiaries
Schedule of Investments [Line Items]
Number of subsidiaries | subsidiaries	2
Number of board members | board_members	7
Number of TILC designated board members | board_members	2
Carrying value of investment in partially-owned subsidiary	$ 228.2
Weighted average ownership interest in partially-owned subsidiary	39.00%
Weighted average ownership interest by institutional investors	61.00%
TRIP Holdings
Schedule of Investments [Line Items]
Date through which equity funding is committed	May 2016
Remaining equity commitment outstanding	$ 5.7
Remaining equity commitment outstanding from third parties	$ 12.9
Date through which equity is committed, extended date	May 2019