Indebtedness (Tables)

12 Months Ended

Dec. 31, 2017

Debt Disclosure [Abstract]

Required principal payments during the next five years and thereafter

The required principal payments due during the next five years and thereafter under all our outstanding debt at December 31, 2017 are as follows:

2018	$	398,000
2019	400,000
2020	—
2021	400,000
2022	500,000
Thereafter	2,350,000
	$	4,048,000