Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2018
Income Tax Disclosure
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability			$ (20,300,000)
Effective tax rate percent	976.20%	40.10%	4449.30%	40.10%
Unrecognized tax benefits	$ 0		$ 0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	$ 1,600,000		$ 1,600,000
Scenario, Forecast [Member]
Income Tax Disclosure
Statutory tax rate					28.10%