Other Assets - Unconsolidated Joint Ventures (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017 building LLCs	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Equity Method Investments [Roll Forward]
Net LLC investments, beginning of period		$ 8,500
Equity income (loss) recognized during the period		(19)	$ 4	$ 7
Owner distributions		(400)	(200)
Net LLC investments, end of period		8,100	8,500
Parking Garages [Member]
Property, Plant and Equipment [Line Items]
Number of LLCs | LLCs	2
Number of parking garages | building	2
Number of buildings acquired | building	3
Equity Method Investments [Roll Forward]
Net LLC investments, beginning of period		8,500	8,700
Equity income (loss) recognized during the period		0	0
Net LLC investments, end of period		$ 8,100	$ 8,500	$ 8,700