|
Commitments and Contingencies - Additional Information (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | 12 Months Ended | |||||
|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2012
|
Sep. 30, 2012
|
Jun. 30, 2012
|
Mar. 31, 2012
|
Sep. 30, 2012
|
Dec. 31, 2012
|
Dec. 31, 2011
|
Dec. 31, 2010
|
|
| Commitments and Contingencies Disclosure [Abstract] | ||||||||
| Rent expense | $ 101.1 | $ 83.7 | $ 66.9 | |||||
| Guaranteed residual value of operating leases | 28.7 | 28.7 | ||||||
| Gain on lawsuit settlements | $ 0.7 | $ 0.5 | $ 8.4 | $ 8.3 | $ 17.2 | $ 17.9 | ||
| Number of defendants class action is pending against | 2 | 2 | ||||||