Taxes - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017 USD ($)
Income Taxes [Line Items]
Tax act, tax benefit due to net deferred tax liabilities	$ 8,000,000
Percentage prohibited transaction tax for not meeting the requirements of statutory relief	100.00%
Federal
Income Taxes [Line Items]
Estimated operating loss carry forwards	$ (57,000,000)
NOL carry forwards, expiring year	2029
NOL carry forwards	$ 0
State and Local Jurisdiction
Income Taxes [Line Items]
NOL carry forwards	$ 1,260,000,000