Summary of Significant Accounting Policies (Details) (USD $) In Millions, except Share data	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011
Summary of Significant Accounting Policies (Textuals) [Abstract]
Reclassification of purchase of additional interest in TRIP holdings	$ 15.5
Repurchase program commenced for repurchases of authorized common stock shares		200
Repurchase of common stock, shares	0	0
Capital in Excess of Par Value
Summary of Significant Accounting Policies (Textuals) [Abstract]
Reclassification of purchase of additional interest in TRIP holdings		15.5
Accumulated Other Comprehensive Loss
Summary of Significant Accounting Policies (Textuals) [Abstract]
Reclassification of purchase of additional interest in TRIP holdings		$ (15.5)