Notes Payable and Long-Term Debt - Summary of Notes Payable and Long-Term Debt (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Notes payable and long-term debt
Total debt	$ 594.4	$ 706.0
Less debt (premium) discount	(0.2)	(0.4)
Total debt (contractual)	594.2	705.6
Less current portion	(47.7)	(74.5)
Add debt premium (discount)	0.2	0.4
Long-term debt	546.7	631.5
Revolving Credit Loans, (2.35% for 2015 and 2.37% for 2014)
Notes payable and long-term debt
Total debt	$ 130.4	$ 169.8
Loan interest rate (in percent)	2.35%	2.37%
6.90%, payable through 2020
Notes payable and long-term debt
Total debt	$ 75.0	$ 80.0
Loan interest rate (in percent)	6.90%	6.90%
5.55%, payable through 2026
Notes payable and long-term debt
Total debt	$ 47.0	$ 50.0
Loan interest rate (in percent)	5.55%	5.55%
5.53%, payable through 2024
Notes payable and long-term debt
Total debt	$ 31.5	$ 37.5
Loan interest rate (in percent)	5.53%	5.53%
5.56%, payable through 2026
Notes payable and long-term debt
Total debt	$ 25.0	$ 25.0
Loan interest rate (in percent)	5.56%	5.56%
3.90%, payable through 2024
Notes payable and long-term debt
Total debt	$ 75.0	$ 75.0
Loan interest rate (in percent)	3.90%	3.90%
4.35%, payable through 2026
Notes payable and long-term debt
Total debt	$ 23.4	$ 25.0
Loan interest rate (in percent)	4.35%	4.35%
4.15%, payable through 2024, secured by Pearl Highlands Center
Notes payable and long-term debt
Total debt	$ 92.3	$ 93.6
Loan interest rate (in percent)	4.15%	4.15%
LIBOR plus 1.5% payable through 2021, secured by Kailua Town Center III
Notes payable and long-term debt
Total debt	$ 11.0	$ 11.2
LIBOR plus 1.5% payable through 2021, secured by Kailua Town Center III | LIBOR
Notes payable and long-term debt
Basis spread on variable rate	1.50%	1.50%
LIBOR plus 2.66%, payable through 2016, secured by The Shops at Kukui'ula
Notes payable and long-term debt
Total debt	$ 37.9	$ 40.5
Loan interest rate (in percent)	2.83%	2.82%
LIBOR plus 2.66%, payable through 2016, secured by The Shops at Kukui'ula | LIBOR
Notes payable and long-term debt
Basis spread on variable rate	2.66%	2.66%
LIBOR plus 2.63%, payable through 2016, secured by Kahala Estate Properties
Notes payable and long-term debt
Total debt	$ 8.2	$ 35.2
Loan interest rate (in percent)	2.82%	2.78%
LIBOR plus 2.63%, payable through 2016, secured by Kahala Estate Properties | LIBOR
Notes payable and long-term debt
Basis spread on variable rate	2.63%	2.63%
5.39%, payable through 2015, secured by Waianae Mall
Notes payable and long-term debt
Total debt	$ 0.0	$ 19.1
Loan interest rate (in percent)	5.39%	5.39%
5.19%, payable through 2019
Notes payable and long-term debt
Total debt	$ 8.8	$ 10.2
Loan interest rate (in percent)	5.19%	5.19%
6.38%, payable through 2017, secured by Midstate Hayes
Notes payable and long-term debt
Total debt	$ 8.3	$ 8.3
Loan interest rate (in percent)	6.38%	6.38%
LIBOR plus 1.0% payable through 2021, secured by asphalt terminal
Notes payable and long-term debt
Total debt	$ 7.2	$ 8.0
LIBOR plus 1.0% payable through 2021, secured by asphalt terminal | LIBOR
Notes payable and long-term debt
Basis spread on variable rate	1.00%	1.00%
1.85%, payable through 2017
Notes payable and long-term debt
Total debt	$ 5.9	$ 7.9
Loan interest rate (in percent)	1.85%	1.85%
3.31%, payable through 2018
Notes payable and long-term debt
Total debt	$ 5.0	$ 6.3
Loan interest rate (in percent)	3.31%	3.31%
2.00%, payable through 2018
Notes payable and long-term debt
Total debt	$ 1.7	$ 2.2
Loan interest rate (in percent)	2.00%	2.00%
2.65%, payable through 2016
Notes payable and long-term debt
Total debt	$ 0.8	$ 1.2
Loan interest rate (in percent)	2.65%	2.65%