Share-Based Compensation (Details) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | 9 Months Ended | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
|
Sep. 30, 2011
|
Sep. 30, 2012
1997 Plan, 2003 Plan and 2011 Plan [Member]
Y
|
Dec. 31, 2011
1997 Plan, 2003 Plan and 2011 Plan [Member]
|
Jul. 31, 2012
Cash Awards [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
Issuance of NTP [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
First Anniversary of NTP [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
Second Anniversary of NTP [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
Third Anniversary of NTP [Member]
|
Jul. 31, 2012
Restricted Stock [Member]
Fourth Anniversary of NTP [Member]
|
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||||||
Share-Based Compensation Arrangement By Share-Based Payment Award, Value of Cash Awards Authorized | $ 60 | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | 10 | ||||||||||||
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Percentage | 35.00% | 10.00% | 15.00% | 15.00% | 25.00% | ||||||||
Total share-based compensation expense recognized | 49.8 | 2.3 | 54.0 | 16.6 | |||||||||
Total share-based compensation capitalized | 2.2 | ||||||||||||
Total unrecognized compensation cost related to non-vested share-based compensation | 94.7 | 7.7 | |||||||||||
Recognition period for total unrecognized compensation expense | 4 | ||||||||||||
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition | 3.8 | ||||||||||||
Proceeds from the exercise of stock options | $ 0.8 | $ 0.8 | $ 0.8 |