Basis of Presentation and Accounting Policies Adoption of New Accounting Standards (Details)
$ in Thousands
Dec. 31, 2017
|Accounting Changes and Error Corrections [Abstract]|
|Cumulative Effect of New Accounting Principle in Period of Adoption||$ (2,467)|
Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.
No definition available.