Notes Receivable - General Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate carrying values	$ 99,900		$ 110,135
Retained earnings	(545,104)		(495,514)
Credit loss	$ 5,828
ASU 2016-13 [Member] | Restatement Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained earnings		$ (5,300)
Bonds A Series [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity date of notes receivable	Jul. 01, 2034
Bonds B Series [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maturity date of notes receivable	Sep. 01, 2037
Credit loss	$ 5,828
Bonds B Series [Member] | ASU 2016-13 [Member] | Restatement Adjustment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained earnings		$ (5,200)
Bonds A and B Series [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate carrying values	99,900		110,100
Credit loss reserve	$ 11,000		$ 0