Segments - Net Income of Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information
Rental revenues	$ 24,251	$ 19,908	$ 47,534	$ 38,098
Rental expenses	5,071	4,631	10,400	9,391
Real estate taxes	2,382	1,959	4,731	3,616
Segment revenues	33,200	47,066	70,003	76,137
Segment expenses	32,025	45,283	67,062	73,425
Net operating income	6,710	6,625	12,709	11,920
Operating Segments
Segment Reporting Information
Net operating income	17,973	15,101	35,344	27,803
Operating Segments | Office real estate
Segment Reporting Information
Rental revenues	5,299	8,052	10,820	15,755
Rental expenses	1,298	1,704	2,754	3,458
Real estate taxes	526	803	1,065	1,494
Net operating income	3,475	5,545	7,001	10,803
Operating Segments | Retail real estate
Segment Reporting Information
Rental revenues	14,113	7,567	27,145	14,192
Rental expenses	2,220	1,346	4,556	2,745
Real estate taxes	1,330	704	2,614	1,270
Net operating income	10,563	5,517	19,975	10,177
Operating Segments | Multifamily residential real estate
Segment Reporting Information
Rental revenues	4,839	4,289	9,569	8,151
Rental expenses	1,553	1,581	3,090	3,188
Real estate taxes	526	452	1,052	852
Net operating income	2,760	2,256	5,427	4,111
Operating Segments | General contracting and real estate services
Segment Reporting Information
Segment revenues	33,200	47,066	70,003	76,137
Segment expenses	32,025	45,283	67,062	73,425
Net operating income	$ 1,175	$ 1,783	$ 2,941	$ 2,712