Consolidated Balance Sheets (Parenthetical) (USD $) In Millions	Sep. 30, 2011		Dec. 31, 2010
Assets
Property, plant and equipment of TRIP Holdings	$ 5,422.7	[1]	$ 5,202.2
Accumulated depreciation on property, plant and equipment of TRIP Holdings	1,191.7	[1]	1,090.2
Restricted cash	229.4	[1]	207.1
Debt:
Debt unamortized discount	102.7	[1]	111.1
Stockholders' equity:
Preferred stock, shares authorized	1.5	[1]	1.5
Preferred stock, shares unissued	1.5	[1]	1.5
Common stock, shares authorized	200.0	[1]	200.0
TRIP Holdings [Member]
Assets
Property, plant and equipment of TRIP Holdings	1,273.5	[1]	1,282.1
Accumulated depreciation on property, plant and equipment of TRIP Holdings	115.6	[1]	90.3
Restricted cash	$ 61.5	[1]	$ 46.0

[1] Unaudited