Net Income Per Common Share (Narrative) - shares shares in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Stock Options | ||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||
| Average outstanding options | 0.0 | 0.0 |