Description of the Business and Summary of Significant Accounting Policies - New Accounting Guidance (Details) - Scenario, Forecast $ in Millions	Jan. 01, 2019 USD ($)
Minimum | Lease assets
Segment Reporting Information [Line Items]
Estimate of additional assets and liabilities with adoption of ASC 842	$ 115.0
Minimum | Lease liabilities
Segment Reporting Information [Line Items]
Estimate of additional assets and liabilities with adoption of ASC 842	115.0
Maximum | Lease assets
Segment Reporting Information [Line Items]
Estimate of additional assets and liabilities with adoption of ASC 842	145.0
Maximum | Lease liabilities
Segment Reporting Information [Line Items]
Estimate of additional assets and liabilities with adoption of ASC 842	$ 145.0