Notes Payable and Other Debt - Schedule of Notes Payable and Long-term Debt (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, gross	$ 763,900,000		$ 763,900,000		$ 705,200,000
Unamortized debt premium (discount)	0		0		(100,000)
Unamortized debt issuance costs	(300,000)		(300,000)		(500,000)
Total debt (carrying value)	763,600,000		763,600,000		704,600,000
Capitalized interest costs	0	$ 200,000	200,000	$ 800,000
Secured:
Debt Instrument [Line Items]
Long-term debt, gross	219,300,000		219,300,000		223,300,000
Secured: | Kailua Town Center
Debt Instrument [Line Items]
Long-term debt, gross	$ 9,900,000		$ 9,900,000		10,200,000
Secured: | Kailua Town Center | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.50%
Swapped maturity fixed interest rate	5.95%		5.95%
Secured: | Kailua Town Center #2
Debt Instrument [Line Items]
Long-term debt, gross	$ 4,500,000		$ 4,500,000		4,600,000
Stated interest rate	3.15%		3.15%
Secured: | Heavy Equipment Financing
Debt Instrument [Line Items]
Long-term debt, gross	$ 3,100,000		$ 3,100,000		3,600,000
Secured: | Heavy Equipment Financing | Minimum
Debt Instrument [Line Items]
Stated interest rate	4.08%		4.08%
Secured: | Heavy Equipment Financing | Maximum
Debt Instrument [Line Items]
Stated interest rate	5.00%		5.00%
Secured: | Laulani Village
Debt Instrument [Line Items]
Long-term debt, gross	$ 61,600,000		$ 61,600,000		62,000,000.0
Stated interest rate	3.93%		3.93%
Secured: | Pearl Highlands
Debt Instrument [Line Items]
Long-term debt, gross	$ 81,900,000		$ 81,900,000		83,400,000
Stated interest rate	4.15%		4.15%
Secured: | Manoa Marketplace
Debt Instrument [Line Items]
Long-term debt, gross	$ 58,300,000		$ 58,300,000		59,500,000
Secured: | Manoa Marketplace | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.35%
Swapped maturity fixed interest rate	3.14%		3.14%
Unsecured:
Debt Instrument [Line Items]
Long-term debt, gross	$ 363,600,000		$ 363,600,000		383,200,000
Unsecured: | Series D Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 0		$ 0		16,200,000
Stated interest rate	0.069%		0.069%
Unsecured: | Bank syndicated loan
Debt Instrument [Line Items]
Long-term debt, gross	$ 50,000,000.0		$ 50,000,000.0		50,000,000.0
Unsecured: | Bank syndicated loan | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.80%
Swapped maturity fixed interest rate	3.15%		3.15%
Unsecured: | Series A Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 28,400,000		$ 28,400,000		28,500,000
Stated interest rate	0.0553%		0.0553%
Unsecured: | Series J Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 10,000,000.0		$ 10,000,000.0		10,000,000.0
Stated interest rate	0.0466%		0.0466%
Unsecured: | Series B Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 46,000,000.0		$ 46,000,000.0		46,000,000.0
Stated interest rate	0.0555%		0.0555%
Unsecured: | Series C Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 22,000,000.0		$ 22,000,000.0		23,000,000.0
Stated interest rate	0.0556%		0.0556%
Unsecured: | Series F Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 19,700,000		$ 19,700,000		22,000,000.0
Stated interest rate	0.0435%		0.0435%
Unsecured: | Series H Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 50,000,000.0		$ 50,000,000.0		50,000,000.0
Stated interest rate	0.0404%		0.0404%
Unsecured: | Series K Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 34,500,000		$ 34,500,000		34,500,000
Stated interest rate	0.0481%		0.0481%
Unsecured: | Series G Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 35,000,000.0		$ 35,000,000.0		35,000,000.0
Stated interest rate	0.0388%		0.0388%
Unsecured: | Series L Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 18,000,000.0		$ 18,000,000.0		18,000,000.0
Stated interest rate	0.0489%		0.0489%
Unsecured: | Series I Note
Debt Instrument [Line Items]
Long-term debt, gross	$ 25,000,000.0		$ 25,000,000.0		25,000,000.0
Stated interest rate	0.0416%		0.0416%
Unsecured: | Term Loan 5
Debt Instrument [Line Items]
Long-term debt, gross	$ 25,000,000.0		$ 25,000,000.0		25,000,000.0
Stated interest rate	0.043%		0.043%
Revolving Credit Facilities:
Debt Instrument [Line Items]
Long-term debt, gross	$ 181,000,000.0		$ 181,000,000.0		98,700,000
Revolving Credit Facilities: | GLP Asphalt revolving credit facility
Debt Instrument [Line Items]
Long-term debt, gross	0		$ 0		0
Revolving Credit Facilities: | GLP Asphalt revolving credit facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.25%
Revolving Credit Facilities: | A&B Revolver
Debt Instrument [Line Items]
Long-term debt, gross	$ 181,000,000.0		$ 181,000,000.0		$ 98,700,000
Revolving Credit Facilities: | A&B Revolver | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			1.85%