Income Taxes (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	May 11, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0	$ 0
Interest and penalty payments	0	0
Current federal tax benefits	0	0
Current state tax benefits	$ 0	$ 0
Income Taxes [Line Items]
Ownership percentage, threshold for utilization of net operating losses carryforward	50.00%			50.00%
Ownership percentage, period for utilization of net operating losses carryforwards	3 years
Deferred tax assets, operating loss carryforwards, annual limitation	$ 200,000
PHS
Income Taxes [Line Items]
Deferred tax assets, operating loss carryforwards, annual limitation				$ 90,000
Federal
Income Taxes [Line Items]
Operating loss carryforwards, subject to expiration			$ 19,900,000
Federal | PHS
Income Taxes [Line Items]
Operating loss carryforwards				1,870,000
Federal | Operating Loss Carryforwards
Income Taxes [Line Items]
Deferred tax assets valuation allowance	173,100,000
State
Income Taxes [Line Items]
Operating loss carryforwards, subject to expiration			$ 19,300,000
State | PHS
Income Taxes [Line Items]
Operating loss carryforwards				$ 1,860,000
State | Operating Loss Carryforwards
Income Taxes [Line Items]
Deferred tax assets valuation allowance	$ 140,400,000