Income Taxes Change in Unrecognized Tax Benefits (Details) $ in Millions |
Mar. 31, 2017
USD ($)
|
|---|---|
| Maximum [Member] | |
| Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] | |
| Decrease in unrecognized tax benefits is reasonably possible | $ 35.0 |
| Minimum [Member] | |
| Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] | |
| Decrease in unrecognized tax benefits is reasonably possible | $ 25.0 |