Income Taxes - Summary of Federal Net Operating Loss Carryforwards and Related Deferred Income Tax Assets (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Deferred Tax Asset	$ 52.2	$ 30.5
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
NOL Carry-forwards	149.2
Deferred Tax Asset	52.2
Internal Revenue Service (IRS) [Member] | 2020 [Member]
Income Tax Contingency [Line Items]
NOL Carry-forwards	7.8
Deferred Tax Asset	2.7
Internal Revenue Service (IRS) [Member] | 2021 through 2025 [Member]
Income Tax Contingency [Line Items]
NOL Carry-forwards	30.5
Deferred Tax Asset	10.7
Internal Revenue Service (IRS) [Member] | 2026 through 2030 [Member]
Income Tax Contingency [Line Items]
NOL Carry-forwards	29.9
Deferred Tax Asset	10.5
Internal Revenue Service (IRS) [Member] | 2031 through 2032 [Member]
Income Tax Contingency [Line Items]
NOL Carry-forwards	81.0
Deferred Tax Asset	$ 28.3