Related-Party Transactions (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended
	Dec. 14, 2011	Dec. 31, 2011	Dec. 14, 2011 TCD	Dec. 31, 2011 ROS TCD
Related party transaction
Equity interest sold (as a percent)	100.00%		100.00%	100.00%
Cash payment to be received as consideration from sale of equity interest in TCD		$ 27.0	$ 27.0	$ 27.0
Contingent consideration to be received in future from sale of equity interest in TCD		$ 3.0	$ 3.0	$ 3.0