Investments in Partnerships (Schedule of Principal Payments Based On Respective Partnership Interest) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	$ 30,096
Balloon Payments	202,259
Total	232,355
Property Total	509,314
Equity method investments unamortized debt costs	2,224
Secured Debt Equity Method Investments Net	507,090	$ 513,139
2014 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	4,204
Balloon Payments	0
Total	4,204
Property Total	8,453
2015 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	4,386
Balloon Payments	0
Total	4,386
Property Total	8,822
2016 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	4,049
Balloon Payments	41,170
Total	45,219
Property Total	91,945
2017 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	3,738
Balloon Payments	21,500
Total	25,238
Property Total	93,476
2018 [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	3,620
Balloon Payments	33,502
Total	37,122
Property Total	74,245
2019 and Thereafter [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal Amortization	10,099
Balloon Payments	106,087
Total	116,186
Property Total	$ 232,373