Long-Term Debt - Schedule of Financial Covenants (Details)	6 Months Ended
	Jun. 30, 2018 USD ($)
Debt Disclosure [Abstract]
Leverage ratio, actual	2.89
Covenant requirement, total leverage ratio	3.75
Debt service coverage ratio, actual	3.40
Minimum debt service coverage ratio	2.00
Covenant, liquidity balance, actual	$ 139,333,000
Debt instrument covenants minimum liquidity amount	$ 25,000,000