Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Long-term debt, carrying value	$ 705,863		$ 713,727
Due to Related Parties	84,000	$ 86,900
Related Party Debt	85,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Long-term debt fair value	688,900	714,300
Long-term debt, carrying value	705,900	713,700
Senior notes | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Long-term debt fair value	484,200	497,800
Mortgage loans | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Long-term debt fair value	$ 204,700	$ 216,500