Subsequent Events (Details) (Subsequent Event, USD $) In Millions, unless otherwise specified	Apr. 30, 2013
Tranche B Term Loans
Subsequent Events
Senior Notes	$ 1,372.0
China Auto
Subsequent Events
Ownership percentage acquired	10.00%
Ownership percentage - Diluted	18.64%
LIBOR | Minimum | Tranche B Term Loans
Subsequent Events
Basis spread on variable rate	100.00%
LIBOR | Minimum | Tranche B-2 Term Loans
Subsequent Events
Basis spread on variable rate	75.00%
LIBOR | Maximum | Tranche B Term Loans
Subsequent Events
Basis spread on variable rate	275.00%
LIBOR | Maximum | Tranche B-2 Term Loans
Subsequent Events
Basis spread on variable rate	225.00%
Alternative Base Rate | Maximum | Tranche B Term Loans
Subsequent Events
Basis spread on variable rate	175.00%
Alternative Base Rate | Maximum | Tranche B-2 Term Loans
Subsequent Events
Basis spread on variable rate	125.00%