Stock Compensation - Additional Information (Details)
shares in Millions, $ in Millions |
|
3 Months Ended |
|
Mar. 31, 2018
USD ($)
perf_measure
|
Mar. 31, 2018
USD ($)
perf_measure
shares
|
Mar. 31, 2017
USD ($)
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Number of performance measures | perf_measure |
2
|
2
|
|
| Cash received from exercise of stock options |
|
$ 1
|
|
| Options exercised in the period | shares |
|
0.1
|
|
| Cash paid to settle SARs and RSUs |
|
$ 2
|
|
| Stock compensation expense |
|
4
|
$ 4
|
| Total unrecognized compensation cost related to nonvested awards granted and expected to vest |
$ 39
|
$ 39
|
|
| Weighted-average period in which the total unrecognized compensation cost is expected to be recognized |
2 years 2 months 12 days
|
|
|
| Restricted Stock Units (RSUs) [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Shares issued in period | shares |
|
0.4
|
|
| Performance Share Units [Member] |
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
|
|
|
| Shares issued in period | shares |
|
0.2
|
|