Fair Value Measurement - Additional Information (Details)	Sep. 30, 2019	Dec. 31, 2018
Minimum
Fair Value Disclosures
Discount rates used to estimate fair value of mortgages and notes payable	3.60	4.82
Maximum
Fair Value Disclosures
Discount rates used to estimate fair value of mortgages and notes payable	3.60	4.83

Value of input used to measure long-term debt.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

Name:	us-gaap_LongTermDebtMeasurementInput
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant