Income Taxes - (Narrative) (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 3,000,000	$ 50,000	$ 6,830,000	$ 177,000
Reduction of deferred tax assets	2,500,000		5,600,000
State income tax expense	500,000		1,200,000
Net operating loss carryforwards	$ 0	$ 0	$ 0	$ 0
Corporate income tax rate			21.00%		35.00%