Schedule III - REAL ESTATE AND ACCUMLATED DEPRECIATION (Information by Property) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	$ 2,690,747
Initial Cost
Land	2,478,353
Buildings and Improvements	1,260,426
Costs Capitalized Subsequent to Acquisition
Land	(487,856)
Building and Improvements	1,728,917
Gross Amounts at Which Carried at Close of Period
Land	1,990,497
Building and Improvements	2,989,343
Total	4,979,840	$ 4,774,632	$ 4,116,556	$ 3,024,833
Accumulated Depreciation	(245,814)	(232,969)	$ (157,182)	$ (111,728)
Deferred Financing Costs	(11,934)	$ (12,392)
Aggregate cost of land, building and improvements for federal income tax purposes	4,000,000
Ae'o
Initial Cost
Land	9,795
Buildings and Improvements	85,046
Costs Capitalized Subsequent to Acquisition
Land	(9,795)
Building and Improvements	9,795
Gross Amounts at Which Carried at Close of Period
Building and Improvements	94,841
Total	94,841
HHC 2978 Self-Storage Woodlands, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	3,708
Initial Cost
Land	878
Buildings and Improvements	6,802
Costs Capitalized Subsequent to Acquisition
Land	(878)
Building and Improvements	878
Gross Amounts at Which Carried at Close of Period
Building and Improvements	7,680
Total	7,680
HHC 242 Self-Storage Woodlands, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	1,715
Initial Cost
Land	124
Buildings and Improvements	5,498
Costs Capitalized Subsequent to Acquisition
Land	(124)
Building and Improvements	124
Gross Amounts at Which Carried at Close of Period
Building and Improvements	5,622
Total	5,622
Allentowne
Initial Cost
Land	25,575
Costs Capitalized Subsequent to Acquisition
Land	(25,575)
Building and Improvements	25,491
Gross Amounts at Which Carried at Close of Period
Building and Improvements	25,491
Total	25,491
Anaha Condominiums
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	114,954
Initial Cost
Land	5,546
Buildings and Improvements	47,450
Costs Capitalized Subsequent to Acquisition
Land	(5,546)
Building and Improvements	5,546
Gross Amounts at Which Carried at Close of Period
Building and Improvements	52,996
Total	52,996
Bridgeland
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	65,000
Initial Cost
Land	257,222
Costs Capitalized Subsequent to Acquisition
Land	184,376
Building and Improvements	1,617
Gross Amounts at Which Carried at Close of Period
Land	441,598
Building and Improvements	1,617
Total	443,215
Accumulated Depreciation	(744)
Bridges at Mint Hill LLC
Costs Capitalized Subsequent to Acquisition
Building and Improvements	21,713
Gross Amounts at Which Carried at Close of Period
Building and Improvements	21,713
Total	21,713
Century Plaza
Initial Cost
Land	3,164
Buildings and Improvements	28,514
Costs Capitalized Subsequent to Acquisition
Land	(3,164)
Building and Improvements	(24,309)
Gross Amounts at Which Carried at Close of Period
Building and Improvements	4,205
Total	4,205
Circle T Ranch
Costs Capitalized Subsequent to Acquisition
Building and Improvements	96
Gross Amounts at Which Carried at Close of Period
Building and Improvements	96
Total	96
70 Columbia Corporate Center
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	100,000
Initial Cost
Land	24,685
Buildings and Improvements	94,824
Costs Capitalized Subsequent to Acquisition
Building and Improvements	12,212
Gross Amounts at Which Carried at Close of Period
Land	24,685
Building and Improvements	107,036
Total	131,721
Accumulated Depreciation	(8,188)
Columbia Offices
Initial Cost
Land	1,575
Buildings and Improvements	28,447
Costs Capitalized Subsequent to Acquisition
Building and Improvements	(7,115)
Gross Amounts at Which Carried at Close of Period
Land	1,575
Building and Improvements	21,332
Total	22,907
Accumulated Depreciation	(5,440)
Columbia Regional Building
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	22,188
Initial Cost
Buildings and Improvements	28,865
Costs Capitalized Subsequent to Acquisition
Building and Improvements	318
Gross Amounts at Which Carried at Close of Period
Building and Improvements	29,183
Total	29,183
Accumulated Depreciation	(2,775)
Cottonwood Mall
Initial Cost
Land	7,613
Buildings and Improvements	42,987
Costs Capitalized Subsequent to Acquisition
Land	(7,613)
Building and Improvements	(21,472)
Gross Amounts at Which Carried at Close of Period
Building and Improvements	21,515
Total	21,515
Cottonwood Square
Initial Cost
Land	1,558
Buildings and Improvements	4,339
Costs Capitalized Subsequent to Acquisition
Building and Improvements	957
Gross Amounts at Which Carried at Close of Period
Land	1,558
Building and Improvements	5,296
Total	6,854
Accumulated Depreciation	(2,061)
Creekside Park Village Center
Costs Capitalized Subsequent to Acquisition
Land	1,323
Building and Improvements	16,012
Gross Amounts at Which Carried at Close of Period
Land	1,323
Building and Improvements	16,012
Total	17,335
Accumulated Depreciation	(895)
Downtown Summerlin Las Vegas, NV
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	306,566
Costs Capitalized Subsequent to Acquisition
Land	30,855
Building and Improvements	380,237
Gross Amounts at Which Carried at Close of Period
Land	30,855
Building and Improvements	380,237
Total	411,092
Accumulated Depreciation	(26,622)
Embassy Suites at Hughes Landing Woodlands, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	29,461
Initial Cost
Buildings and Improvements	6,752
Costs Capitalized Subsequent to Acquisition
Land	1,818
Building and Improvements	35,761
Gross Amounts at Which Carried at Close of Period
Land	1,818
Building and Improvements	42,513
Total	44,331
Accumulated Depreciation	(1,541)
Hughes Landing Retail
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	35,000
Costs Capitalized Subsequent to Acquisition
Land	5,184
Building and Improvements	32,562
Gross Amounts at Which Carried at Close of Period
Land	5,184
Building and Improvements	32,562
Total	37,746
Accumulated Depreciation	(1,694)
One Hughes Landing
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	52,000
Costs Capitalized Subsequent to Acquisition
Land	1,678
Building and Improvements	35,029
Gross Amounts at Which Carried at Close of Period
Land	1,678
Building and Improvements	35,029
Total	36,707
Accumulated Depreciation	(4,823)
Two Hughes Landing
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	48,000
Costs Capitalized Subsequent to Acquisition
Land	1,269
Building and Improvements	35,015
Gross Amounts at Which Carried at Close of Period
Land	1,269
Building and Improvements	35,015
Total	36,284
Accumulated Depreciation	(3,612)
Three Hughes Landing
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	35,053
Initial Cost
Buildings and Improvements	46,372
Costs Capitalized Subsequent to Acquisition
Land	2,626
Building and Improvements	13,370
Gross Amounts at Which Carried at Close of Period
Land	2,626
Building and Improvements	59,742
Total	62,368
Accumulated Depreciation	(147)
Hughes Landing Boulevard 1725
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	52,830
Initial Cost
Land	1,351
Buildings and Improvements	36,764
Costs Capitalized Subsequent to Acquisition
Building and Improvements	25,795
Gross Amounts at Which Carried at Close of Period
Land	1,351
Building and Improvements	62,559
Total	63,910
Accumulated Depreciation	(3,080)
Hughes Landing Boulevard 1735
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	52,818
Initial Cost
Land	3,709
Buildings and Improvements	123,846
Costs Capitalized Subsequent to Acquisition
Building and Improvements	(25,887)
Gross Amounts at Which Carried at Close of Period
Land	3,709
Building and Improvements	97,959
Total	101,668
Accumulated Depreciation	(5,052)
IBM Building
Initial Cost
Land	3,326
Buildings and Improvements	23,123
Costs Capitalized Subsequent to Acquisition
Building and Improvements	8,397
Gross Amounts at Which Carried at Close of Period
Land	3,326
Building and Improvements	31,520
Total	34,846
Accumulated Depreciation	(8,213)
Ke Kilohana
Initial Cost
Land	2,615
Buildings and Improvements	17,784
Costs Capitalized Subsequent to Acquisition
Land	(2,615)
Building and Improvements	2,615
Gross Amounts at Which Carried at Close of Period
Building and Improvements	20,399
Total	20,399
Kendall Town Center
Costs Capitalized Subsequent to Acquisition
Building and Improvements	19,521
Gross Amounts at Which Carried at Close of Period
Building and Improvements	19,521
Total	19,521
Kewalo Basin Harbor
Initial Cost
Buildings and Improvements	1,735
Costs Capitalized Subsequent to Acquisition
Building and Improvements	671
Gross Amounts at Which Carried at Close of Period
Building and Improvements	2,406
Total	2,406
1701 Lake Robbins
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	4,600
Initial Cost
Land	1,663
Buildings and Improvements	3,725
Costs Capitalized Subsequent to Acquisition
Building and Improvements	8
Gross Amounts at Which Carried at Close of Period
Land	1,663
Building and Improvements	3,733
Total	5,396
Accumulated Depreciation	(227)
Lake Woodlands Drive 2201
Initial Cost
Land	3,755
Costs Capitalized Subsequent to Acquisition
Building and Improvements	47
Gross Amounts at Which Carried at Close of Period
Land	3,755
Building and Improvements	47
Total	3,802
One Lakes Edge
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	68,874
Costs Capitalized Subsequent to Acquisition
Land	1,057
Building and Improvements	81,384
Gross Amounts at Which Carried at Close of Period
Land	1,057
Building and Improvements	81,384
Total	82,441
Accumulated Depreciation	(3,496)
Lakeland Village Center at Bridgeland Cypress, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	9,979
Initial Cost
Buildings and Improvements	11,135
Costs Capitalized Subsequent to Acquisition
Land	2,404
Building and Improvements	1,554
Gross Amounts at Which Carried at Close of Period
Land	2,404
Building and Improvements	12,689
Total	15,093
Accumulated Depreciation	(16)
Lakemoor Volo Land
Initial Cost
Land	321
Costs Capitalized Subsequent to Acquisition
Land	(321)
Building and Improvements	321
Gross Amounts at Which Carried at Close of Period
Building and Improvements	321
Total	321
Landmark Mall
Initial Cost
Land	28,396
Buildings and Improvements	67,235
Costs Capitalized Subsequent to Acquisition
Land	(19,408)
Building and Improvements	(33,081)
Gross Amounts at Which Carried at Close of Period
Land	8,988
Building and Improvements	34,154
Total	43,142
Accumulated Depreciation	(12,754)
Maryland Communities
Initial Cost
Land	457,552
Costs Capitalized Subsequent to Acquisition
Land	(435,177)
Building and Improvements	197
Gross Amounts at Which Carried at Close of Period
Land	22,375
Building and Improvements	197
Total	22,572
Accumulated Depreciation	(143)
One Merriweather Columbia, MD
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	23,589
Initial Cost
Land	1,432
Buildings and Improvements	58,936
Costs Capitalized Subsequent to Acquisition
Land	(1,432)
Building and Improvements	88,863
Gross Amounts at Which Carried at Close of Period
Building and Improvements	147,799
Total	147,799
Millennium Waterway Apartments
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	55,584
Initial Cost
Land	15,917
Buildings and Improvements	56,002
Costs Capitalized Subsequent to Acquisition
Building and Improvements	471
Gross Amounts at Which Carried at Close of Period
Land	15,917
Building and Improvements	56,473
Total	72,390
Accumulated Depreciation	(10,580)
Millennium Six Pines Apartments Woodlands, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	42,500
Initial Cost
Land	4,000
Costs Capitalized Subsequent to Acquisition
Land	7,225
Building and Improvements	54,492
Gross Amounts at Which Carried at Close of Period
Land	11,225
Building and Improvements	54,492
Total	65,717
Accumulated Depreciation	(834)
Two Merriweather Columbia, MD
Initial Cost
Land	1,019
Buildings and Improvements	4,931
Costs Capitalized Subsequent to Acquisition
Land	(1,019)
Building and Improvements	1,019
Gross Amounts at Which Carried at Close of Period
Building and Improvements	5,950
Total	5,950
9303 New Trails
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	12,378
Initial Cost
Land	1,929
Buildings and Improvements	11,915
Costs Capitalized Subsequent to Acquisition
Building and Improvements	2,076
Gross Amounts at Which Carried at Close of Period
Land	1,929
Building and Improvements	13,991
Total	15,920
Accumulated Depreciation	(2,582)
110 N Wacker
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	22,704
Initial Cost
Buildings and Improvements	29,035
Costs Capitalized Subsequent to Acquisition
Land	12,249
Building and Improvements	6,597
Gross Amounts at Which Carried at Close of Period
Land	12,249
Building and Improvements	35,632
Total	47,881
Accumulated Depreciation	(15,119)
One Mall North Columbia, MD
Initial Cost
Land	22,200
Costs Capitalized Subsequent to Acquisition
Land	(14,378)
Building and Improvements	13,016
Gross Amounts at Which Carried at Close of Period
Land	7,822
Building and Improvements	13,016
Total	20,838
Accumulated Depreciation	(31)
Outlet Collection at Elk Grove
Costs Capitalized Subsequent to Acquisition
Building and Improvements	13,759
Gross Amounts at Which Carried at Close of Period
Building and Improvements	13,759
Total	13,759
Accumulated Depreciation	(5)
Outlet Collection at Riverwalk
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	55,778
Initial Cost
Buildings and Improvements	94,513
Costs Capitalized Subsequent to Acquisition
Building and Improvements	562
Gross Amounts at Which Carried at Close of Period
Building and Improvements	95,075
Total	95,075
Accumulated Depreciation	(12,047)
Seaport Tin Building New York, NY
Initial Cost
Buildings and Improvements	8,290
Gross Amounts at Which Carried at Close of Period
Building and Improvements	8,290
Total	8,290
Seaport Mixed-Use New York, NY
Initial Cost
Buildings and Improvements	7,641
Gross Amounts at Which Carried at Close of Period
Building and Improvements	7,641
Total	7,641
85 South Street
Initial Cost
Land	15,913
Buildings and Improvements	8,137
Costs Capitalized Subsequent to Acquisition
Building and Improvements	468
Gross Amounts at Which Carried at Close of Period
Land	15,913
Building and Improvements	8,605
Total	24,518
Accumulated Depreciation	(1,370)
South Street Seaport
Initial Cost
Buildings and Improvements	7,884
Costs Capitalized Subsequent to Acquisition
Building and Improvements	369,868
Gross Amounts at Which Carried at Close of Period
Building and Improvements	377,752
Total	377,752
Accumulated Depreciation	(3,997)
Summerlin
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	40,438
Initial Cost
Land	990,179
Costs Capitalized Subsequent to Acquisition
Land	(107,635)
Building and Improvements	1,157
Gross Amounts at Which Carried at Close of Period
Land	882,544
Building and Improvements	1,157
Total	883,701
Accumulated Depreciation	(567)
3831 Technology Forest
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	22,383
Initial Cost
Land	514
Buildings and Improvements	14,194
Costs Capitalized Subsequent to Acquisition
Building and Improvements	1,703
Gross Amounts at Which Carried at Close of Period
Land	514
Building and Improvements	15,897
Total	16,411
Accumulated Depreciation	(1,645)
The Metropolitan Downtown Columbia Project
Costs Capitalized Subsequent to Acquisition
Building and Improvements	7
Gross Amounts at Which Carried at Close of Period
Building and Improvements	7
Total	7
Woodlands Properties
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	150,000
Initial Cost
Land	267,996
Buildings and Improvements	9,814
Costs Capitalized Subsequent to Acquisition
Land	(43,318)
Building and Improvements	7,685
Gross Amounts at Which Carried at Close of Period
Land	224,678
Building and Improvements	17,499
Total	242,177
Accumulated Depreciation	(2,513)
The Woodlands Hills
Initial Cost
Land	99,284
Costs Capitalized Subsequent to Acquisition
Land	3,738
Gross Amounts at Which Carried at Close of Period
Land	103,022
Total	103,022
Woodlands Parking Garages
Initial Cost
Land	5,857
Costs Capitalized Subsequent to Acquisition
Land	1,529
Building and Improvements	11,728
Gross Amounts at Which Carried at Close of Period
Land	7,386
Building and Improvements	11,728
Total	19,114
Accumulated Depreciation	(796)
The Woodlands Resort and Conference Center
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	70,000
Initial Cost
Land	13,258
Buildings and Improvements	37,983
Costs Capitalized Subsequent to Acquisition
Building and Improvements	75,193
Gross Amounts at Which Carried at Close of Period
Land	13,258
Building and Improvements	113,176
Total	126,434
Accumulated Depreciation	(11,737)
The Westin at the Woodlands Woodlands, TX
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	58,077
Initial Cost
Land	22,473
Costs Capitalized Subsequent to Acquisition
Land	(20,520)
Building and Improvements	88,136
Gross Amounts at Which Carried at Close of Period
Land	1,953
Building and Improvements	88,136
Total	90,089
Accumulated Depreciation	(2,330)
Waiea
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	45,892
Initial Cost
Buildings and Improvements	20,812
Costs Capitalized Subsequent to Acquisition
Building and Improvements	29,307
Gross Amounts at Which Carried at Close of Period
Building and Improvements	50,119
Total	50,119
Ward Gateway Towers
Initial Cost
Land	5,201
Buildings and Improvements	24,069
Costs Capitalized Subsequent to Acquisition
Land	(5,201)
Building and Improvements	5,200
Gross Amounts at Which Carried at Close of Period
Building and Improvements	29,269
Total	29,269
Ward Village
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	238,718
Initial Cost
Land	164,007
Buildings and Improvements	89,321
Costs Capitalized Subsequent to Acquisition
Land	(42,205)
Building and Improvements	171,851
Gross Amounts at Which Carried at Close of Period
Land	121,802
Building and Improvements	261,172
Total	382,974
Accumulated Depreciation	(50,568)
Waterway Garage Retail
Initial Cost
Land	1,342
Buildings and Improvements	4,255
Costs Capitalized Subsequent to Acquisition
Land	(1)
Building and Improvements	1,386
Gross Amounts at Which Carried at Close of Period
Land	1,341
Building and Improvements	5,641
Total	6,982
Accumulated Depreciation	(993)
3 Waterway Square
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	51,590
Initial Cost
Land	748
Costs Capitalized Subsequent to Acquisition
Building and Improvements	42,332
Gross Amounts at Which Carried at Close of Period
Land	748
Building and Improvements	42,332
Total	43,080
Accumulated Depreciation	(7,422)
4 Waterway Square
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	36,249
Initial Cost
Land	1,430
Buildings and Improvements	51,553
Costs Capitalized Subsequent to Acquisition
Building and Improvements	7,016
Gross Amounts at Which Carried at Close of Period
Land	1,430
Building and Improvements	58,569
Total	59,999
Accumulated Depreciation	(11,225)
20/25 Waterway Avenue
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	13,886
Initial Cost
Land	2,346
Buildings and Improvements	8,871
Costs Capitalized Subsequent to Acquisition
Building and Improvements	767
Gross Amounts at Which Carried at Close of Period
Land	2,346
Building and Improvements	9,638
Total	11,984
Accumulated Depreciation	(1,790)
West Windsor
Costs Capitalized Subsequent to Acquisition
Land	53
Building and Improvements	24,859
Gross Amounts at Which Carried at Close of Period
Land	53
Building and Improvements	24,859
Total	24,912
Woodloch Forest 1400
Costs Capitalized Subsequent to Acquisition
Land	1,570
Building and Improvements	14,085
Gross Amounts at Which Carried at Close of Period
Land	1,570
Building and Improvements	14,085
Total	15,655
Accumulated Depreciation	(3,609)
Corporate Segment
REAL ESTATE AND ACCUMULATED DEPRECIATION
Encumbrances	760,169
Initial Cost
Land	885
Buildings and Improvements	1,027
Costs Capitalized Subsequent to Acquisition
Land	(885)
Building and Improvements	39,935
Gross Amounts at Which Carried at Close of Period
Building and Improvements	40,962
Total	40,962
Accumulated Depreciation	$ (12,531)