Notes Receivable and Allowance for Credit Losses - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2020	Dec. 31, 2019	Jan. 01, 2020	Dec. 31, 2018
Notes Receivable and Allowance for Losses [Line Items]
Loan reserves		$ 13,102	$ 4,556		$ 4,685
Loans and financing receivable		102,759	103,054
Financing Receivable, before Allowance for Credit Loss		140,022	133,014
Retained earnings		1,004,744	968,833
Mezzanine & Other Notes Receivable | Impaired Loans
Notes Receivable and Allowance for Losses [Line Items]
Average notes receivable, nonaccrual status		1,700	1,700
Variable Interest Entity, Not Primary Beneficiary | Mezzanine & Other Notes Receivable
Notes Receivable and Allowance for Losses [Line Items]
Loans and financing receivable		124,900	126,500
Variable Interest Entity, Not Primary Beneficiary | Interest Rate Below Market Reduction | Mezzanine & Other Notes Receivable
Notes Receivable and Allowance for Losses [Line Items]
Loans and financing receivable		14,200	16,300
Receivable with Imputed Interest, discount		$ 1,200	$ 1,300
Accounting Standards Update 2016-13
Notes Receivable and Allowance for Losses [Line Items]
Cumulative effect of new accounting principle in period of adoption	[1]			$ (6,831)
Cumulative Effect, Period of Adoption. Adjusted Balance | Accounting Standards Update 2016-13
Notes Receivable and Allowance for Losses [Line Items]
Loan reserves				12,900
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2016-13
Notes Receivable and Allowance for Losses [Line Items]
Loan reserves				8,348
Retained earnings				$ 6,800

[1] Reflects the cumulative effect of ASU 2016-13, Financial Instruments - Credit Losses (Topic 326), which was adopted on January 1, 2020. Refer to Note 1 for additional details.