Income Taxes (Tax Credit Carryforwards) (Details) $ in Millions |
Dec. 31, 2015
USD ($)
|
|---|---|
| Tax Credit Carryforward [Line Items] | |
| Taxable income required for full realization of deferred tax assets | $ 138.8 |
| Federal | Research and development tax credit carryforward | |
| Tax Credit Carryforward [Line Items] | |
| Tax credit carryforward | 4.6 |
| State | Research and development tax credit carryforward | |
| Tax Credit Carryforward [Line Items] | |
| Tax credit carryforward | $ 3.4 |