|
Share-Based Compensation (Details) (USD $)
|
3 Months Ended |
0 Months Ended |
|
Mar. 31, 2015
|
Mar. 31, 2014
|
Mar. 05, 2015
|
| Options |
|
|
|
| Exercised (in shares) |
70,374 |
26,614 |
|
| Performance share units |
|
|
|
| Assumptions used to value stock awards |
|
|
|
| Weighted average grant date fair value (in dollars per share) |
36.76 |
|
|
| Baseline value per common share (in dollars per share) |
29.28 |
|
|
| Expected volatility of common shares (as a percent) |
19.90% |
|
|
| Risk-free interest rate (as a percent) |
0.99% |
|
|
| Restricted shares |
|
|
|
| Share-Based Compensation |
|
|
|
| Stock awards granted (in shares or units) |
177,674 |
|
|
| Aggregate grant date fair value |
5,200,000 |
|
|
| Assumptions used to value stock awards |
|
|
|
| Weighted average grant date fair value (in dollars per share) |
29.46 |
|
|
| Other Share-based Compensation Additional Disclosures |
|
|
|
| Shares vested (in shares) |
127,444 |
|
|
| Weighted average fair value of shares vested (in dollars per share) |
26.01 |
|
|
| Aggregate intrinsic value of restricted common shares, forfeiture restrictions lapsed |
3,700,000 |
|
|
| Options |
|
|
|
| Options |
|
|
|
| Exercised (in shares) |
70,374 |
|
|
| Weighted average exercise price (in dollars per share) |
26.23 |
|
|
| Aggregate intrinsic value of options exercised (in dollars) |
291,000 |
|
|
| 2014 PSU Grants | Performance share units |
|
|
|
| Share-Based Compensation |
|
|
|
| Stock awards granted (in shares or units) |
|
|
45,656 |
| Aggregate grant date fair value |
|
|
$ 1,700,000 |
| Potential earned PSUs payout for defined levels of performance under awards |
|
|
|
| Earned PSUs payout (as a percent of PSUs granted) on 75th or greater percentile rank |
200.00% |
|
|
| Earned PSUs payout (as a percent of PSUs granted) on 50th percentile rank |
100.00% |
|
|
| Earned PSUs payout (as a percent of PSUs granted) on 25th percentile rank |
50.00% |
|
|
| Performance share units granted on percentile rank below 25th (as a percent) |
0.00% |
|
|
| The number of percentile ranks to fall between to earn interpolated PSUs between such percentile ranks, conditioned on the percentile rank exceeding 25% |
2 |
|
|
| A2012PSUGrants [Member] | Performance share units |
|
|
|
| Assumptions used to value stock awards |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Shares issued for Awards Vested in Period |
|
|
40,309 |
| 2013 PSU Grants [Member] | Performance share units | Former Chief Financial Officer [Member] |
|
|
|
| Assumptions used to value stock awards |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Shares issued for Awards Vested in Period |
|
|
15,289 |