Schedule III - Real Estate and Accumulated Depreciation Properties (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	$ 1,645,523
Land, initial cost	999,514
Buildings, equipment & improvement, initial cost	2,099,501
Additions (dispositions) (impairments) subsequent to acquisition	205,978
Land, gross amount	1,005,641
Buildings, equipment & improvement, gross amount	2,299,352
Fair value of Concord resort land received	3,304,993us-gaap_RealEstateGrossAtCarryingValue	2,804,609us-gaap_RealEstateGrossAtCarryingValue
Accumulated depreciation	465,660	409,643
Dallas Retail
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,060
Buildings, equipment & improvement, initial cost	15,281
Additions (dispositions) (impairments) subsequent to acquisition	18,843
Land, gross amount	3,060
Buildings, equipment & improvement, gross amount	34,124
Fair value of Concord resort land received	37,184
Accumulated depreciation	(11,188)
Depreciation life	40 years
Oakview 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	5,215
Buildings, equipment & improvement, initial cost	16,700
Additions (dispositions) (impairments) subsequent to acquisition	59
Land, gross amount	5,215
Buildings, equipment & improvement, gross amount	16,759
Fair value of Concord resort land received	21,974
Accumulated depreciation	(7,122)
Depreciation life	40 years
First Colony 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	15,563
Land, initial cost	0
Buildings, equipment & improvement, initial cost	19,100
Additions (dispositions) (impairments) subsequent to acquisition	67
Land, gross amount	0
Buildings, equipment & improvement, gross amount	19,167
Fair value of Concord resort land received	19,167
Accumulated depreciation	(8,146)
Depreciation life	40 years
Huebner Oaks 14
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,006
Buildings, equipment & improvement, initial cost	13,662
Additions (dispositions) (impairments) subsequent to acquisition	2,058
Land, gross amount	3,006
Buildings, equipment & improvement, gross amount	15,720
Fair value of Concord resort land received	18,726
Accumulated depreciation	(5,853)
Depreciation life	40 years
Lennox Town Center 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	0
Buildings, equipment & improvement, initial cost	12,685
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	0
Buildings, equipment & improvement, gross amount	12,685
Fair value of Concord resort land received	12,685
Accumulated depreciation	(5,233)
Depreciation life	40 years
Mission Valley 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	0
Buildings, equipment & improvement, initial cost	16,028
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	0
Buildings, equipment & improvement, gross amount	16,028
Fair value of Concord resort land received	16,028
Accumulated depreciation	(6,612)
Depreciation life	40 years
Ontario Mills 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	5,521
Buildings, equipment & improvement, initial cost	19,449
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	5,521
Buildings, equipment & improvement, gross amount	19,449
Fair value of Concord resort land received	24,970
Accumulated depreciation	(8,023)
Depreciation life	40 years
Promenade 16 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,021
Buildings, equipment & improvement, initial cost	22,104
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	6,021
Buildings, equipment & improvement, gross amount	22,104
Fair value of Concord resort land received	28,125
Accumulated depreciation	(9,118)
Depreciation life	40 years
Studio 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,023
Buildings, equipment & improvement, initial cost	20,037
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	6,023
Buildings, equipment & improvement, gross amount	20,037
Fair value of Concord resort land received	26,060
Accumulated depreciation	(8,265)
Depreciation life	40 years
West Olive 16 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	4,985
Buildings, equipment & improvement, initial cost	12,601
Additions (dispositions) (impairments) subsequent to acquisition	4,075
Land, gross amount	4,985
Buildings, equipment & improvement, gross amount	16,676
Fair value of Concord resort land received	21,661
Accumulated depreciation	(5,443)
Depreciation life	40 years
Leawood Town Center 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	12,982
Land, initial cost	3,714
Buildings, equipment & improvement, initial cost	12,086
Additions (dispositions) (impairments) subsequent to acquisition	4,110
Land, gross amount	3,714
Buildings, equipment & improvement, gross amount	16,196
Fair value of Concord resort land received	19,910
Accumulated depreciation	(5,172)
Depreciation life	40 years
Gulf Pointe 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	4,304
Buildings, equipment & improvement, initial cost	21,496
Additions (dispositions) (impairments) subsequent to acquisition	76
Land, gross amount	4,304
Buildings, equipment & improvement, gross amount	21,572
Fair value of Concord resort land received	25,876
Accumulated depreciation	(9,123)
Depreciation life	40 years
South Barrington 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,577
Buildings, equipment & improvement, initial cost	27,723
Additions (dispositions) (impairments) subsequent to acquisition	98
Land, gross amount	6,577
Buildings, equipment & improvement, gross amount	27,821
Fair value of Concord resort land received	34,398
Accumulated depreciation	(11,708)
Depreciation life	40 years
Mesquite 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	2,912
Buildings, equipment & improvement, initial cost	20,288
Additions (dispositions) (impairments) subsequent to acquisition	4,885
Land, gross amount	2,912
Buildings, equipment & improvement, gross amount	25,173
Fair value of Concord resort land received	28,085
Accumulated depreciation	(8,568)
Depreciation life	40 years
Hampton Town Center 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,822
Buildings, equipment & improvement, initial cost	24,678
Additions (dispositions) (impairments) subsequent to acquisition	88
Land, gross amount	3,822
Buildings, equipment & improvement, gross amount	24,766
Fair value of Concord resort land received	28,588
Accumulated depreciation	(10,216)
Depreciation life	40 years
Broward 18
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	8,750
Land, initial cost	6,771
Buildings, equipment & improvement, initial cost	9,899
Additions (dispositions) (impairments) subsequent to acquisition	3,845
Land, gross amount	6,771
Buildings, equipment & improvement, gross amount	13,744
Fair value of Concord resort land received	20,515
Accumulated depreciation	(5,794)
Depreciation life	40 years
Raleigh Grande 16 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	5,648
Land, initial cost	2,919
Buildings, equipment & improvement, initial cost	5,559
Additions (dispositions) (impairments) subsequent to acquisition	951
Land, gross amount	2,919
Buildings, equipment & improvement, gross amount	6,510
Fair value of Concord resort land received	9,429
Accumulated depreciation	(2,358)
Depreciation life	40 years
Paradise 24 and XD [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	17,757
Land, initial cost	2,000
Buildings, equipment & improvement, initial cost	13,000
Additions (dispositions) (impairments) subsequent to acquisition	8,512
Land, gross amount	2,000
Buildings, equipment & improvement, gross amount	21,512
Fair value of Concord resort land received	23,512
Accumulated depreciation	(8,515)
Depreciation life	40 years
Aliso Viejo Stadium 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	17,757
Land, initial cost	8,000
Buildings, equipment & improvement, initial cost	14,000
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	8,000
Buildings, equipment & improvement, gross amount	14,000
Fair value of Concord resort land received	22,000
Accumulated depreciation	(5,600)
Depreciation life	40 years
Boise Stadium 22 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	12,648
Land, initial cost	0
Buildings, equipment & improvement, initial cost	16,003
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	0
Buildings, equipment & improvement, gross amount	16,003
Fair value of Concord resort land received	16,003
Accumulated depreciation	(6,401)
Depreciation life	40 years
Mesquite Retail Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,119
Buildings, equipment & improvement, initial cost	990
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	3,119
Buildings, equipment & improvement, gross amount	990
Fair value of Concord resort land received	4,109
Accumulated depreciation	(293)
Depreciation life	40 years
Westminster Promenade [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,204
Buildings, equipment & improvement, initial cost	12,600
Additions (dispositions) (impairments) subsequent to acquisition	9,509
Land, gross amount	6,204
Buildings, equipment & improvement, gross amount	22,109
Fair value of Concord resort land received	28,313
Accumulated depreciation	(7,168)
Depreciation life	40 years
Westminster Promenade 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	6,205
Land, initial cost	5,850
Buildings, equipment & improvement, initial cost	17,314
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	5,850
Buildings, equipment & improvement, gross amount	17,314
Fair value of Concord resort land received	23,164
Accumulated depreciation	(5,663)
Depreciation life	40 years
Woodridge 18 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	9,926
Buildings, equipment & improvement, initial cost	8,968
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	9,926
Buildings, equipment & improvement, gross amount	8,968
Fair value of Concord resort land received	18,894
Accumulated depreciation	(3,475)
Depreciation life	40 years
Cary Crossroads Stadium 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,352
Buildings, equipment & improvement, initial cost	11,653
Additions (dispositions) (impairments) subsequent to acquisition	155
Land, gross amount	3,352
Buildings, equipment & improvement, gross amount	11,808
Fair value of Concord resort land received	15,160
Accumulated depreciation	(4,428)
Depreciation life	40 years
Starlight 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,000
Buildings, equipment & improvement, initial cost	12,809
Additions (dispositions) (impairments) subsequent to acquisition	1,452
Land, gross amount	6,000
Buildings, equipment & improvement, gross amount	14,261
Fair value of Concord resort land received	20,261
Accumulated depreciation	(5,487)
Depreciation life	40 years
Palm Promenade 24 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	7,500
Buildings, equipment & improvement, initial cost	17,750
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	7,500
Buildings, equipment & improvement, gross amount	17,750
Fair value of Concord resort land received	25,250
Accumulated depreciation	(6,619)
Depreciation life	40 years
Gulf Pointe Retail Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,653
Buildings, equipment & improvement, initial cost	1,365
Additions (dispositions) (impairments) subsequent to acquisition	686
Land, gross amount	3,408
Buildings, equipment & improvement, gross amount	2,296
Fair value of Concord resort land received	5,704
Accumulated depreciation	(1,883)
Depreciation life	40 years
Clearview Palace 12 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	0
Buildings, equipment & improvement, initial cost	11,740
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	0
Buildings, equipment & improvement, gross amount	11,740
Fair value of Concord resort land received	11,740
Accumulated depreciation	(3,767)
Depreciation life	40 years
Elmwood Palace 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	5,264
Buildings, equipment & improvement, initial cost	14,820
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	5,264
Buildings, equipment & improvement, gross amount	14,820
Fair value of Concord resort land received	20,084
Accumulated depreciation	(4,755)
Depreciation life	40 years
Hammond Palace 10 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	2,404
Buildings, equipment & improvement, initial cost	6,780
Additions (dispositions) (impairments) subsequent to acquisition	(565)
Land, gross amount	1,839
Buildings, equipment & improvement, gross amount	6,780
Fair value of Concord resort land received	8,619
Accumulated depreciation	(2,175)
Depreciation life	40 years
Houma Palace 10 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	2,404
Buildings, equipment & improvement, initial cost	6,780
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	2,404
Buildings, equipment & improvement, gross amount	6,780
Fair value of Concord resort land received	9,184
Accumulated depreciation	(2,175)
Depreciation life	40 years
Westbank Palace 16 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	4,378
Buildings, equipment & improvement, initial cost	12,330
Additions (dispositions) (impairments) subsequent to acquisition	(112)
Land, gross amount	4,266
Buildings, equipment & improvement, gross amount	12,330
Fair value of Concord resort land received	16,596
Accumulated depreciation	(3,956)
Depreciation life	40 years
Cherrydale [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	1,660
Buildings, equipment & improvement, initial cost	7,570
Additions (dispositions) (impairments) subsequent to acquisition	100
Land, gross amount	1,660
Buildings, equipment & improvement, gross amount	7,670
Fair value of Concord resort land received	9,330
Accumulated depreciation	(2,410)
Depreciation life	40 years
Forum 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	5,975
Buildings, equipment & improvement, initial cost	17,956
Additions (dispositions) (impairments) subsequent to acquisition	3,400
Land, gross amount	5,975
Buildings, equipment & improvement, gross amount	21,356
Fair value of Concord resort land received	27,331
Accumulated depreciation	(8,018)
Depreciation life	40 years
Olathe Studio 30 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	4,000
Buildings, equipment & improvement, initial cost	15,935
Additions (dispositions) (impairments) subsequent to acquisition	2,361
Land, gross amount	4,000
Buildings, equipment & improvement, gross amount	18,296
Fair value of Concord resort land received	22,296
Accumulated depreciation	(5,491)
Depreciation life	40 years
Livonia 20 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	4,500
Buildings, equipment & improvement, initial cost	17,525
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	4,500
Buildings, equipment & improvement, gross amount	17,525
Fair value of Concord resort land received	22,025
Accumulated depreciation	(5,440)
Depreciation life	40 years
Hoffman Center 22 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	0
Buildings, equipment & improvement, initial cost	22,035
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	0
Buildings, equipment & improvement, gross amount	22,035
Fair value of Concord resort land received	22,035
Accumulated depreciation	(6,748)
Depreciation life	40 years
Colonel Glenn 18 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	8,671
Land, initial cost	3,858
Buildings, equipment & improvement, initial cost	7,990
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	3,858
Buildings, equipment & improvement, gross amount	7,990
Fair value of Concord resort land received	11,848
Accumulated depreciation	(2,414)
Depreciation life	40 years
AmStar 16-Macon [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	5,442
Land, initial cost	1,982
Buildings, equipment & improvement, initial cost	5,056
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	1,982
Buildings, equipment & improvement, gross amount	5,056
Fair value of Concord resort land received	7,038
Accumulated depreciation	(1,485)
Depreciation life	40 years
Star Southfield Center [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	8,000
Buildings, equipment & improvement, initial cost	20,518
Additions (dispositions) (impairments) subsequent to acquisition	6,213
Land, gross amount	8,000
Buildings, equipment & improvement, gross amount	26,731
Fair value of Concord resort land received	34,731
Accumulated depreciation	(8,978)
Depreciation life	40 years
South Wind 12 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	4,038
Land, initial cost	1,500
Buildings, equipment & improvement, initial cost	3,526
Additions (dispositions) (impairments) subsequent to acquisition	0
Land, gross amount	1,500
Buildings, equipment & improvement, gross amount	3,526
Fair value of Concord resort land received	5,026
Accumulated depreciation	(1,021)
Depreciation life	40 years
New Roc City [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	6,100
Buildings, equipment & improvement, initial cost	97,696
Additions (dispositions) (impairments) subsequent to acquisition	412
Land, gross amount	6,100
Buildings, equipment & improvement, gross amount	98,108
Fair value of Concord resort land received	104,208
Accumulated depreciation	(30,183)
Depreciation life	40 years
Columbiana Grande Stadium 14 [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	6,912
Land, initial cost	1,000
Buildings, equipment & improvement, initial cost	10,534
Additions (dispositions) (impairments) subsequent to acquisition	(2,447)
Land, gross amount	1,000
Buildings, equipment & improvement, gross amount	8,087
Fair value of Concord resort land received	9,087
Accumulated depreciation	(2,313)
Depreciation life	40 years
Harbour View Marketplace [Member]
Real Estate and Accumulated Depreciation [Line Items]
Encumbrance	0
Land, initial cost	3,382
Buildings, equipment & improvement, initial cost	9,971
Additions (dispositions) (impairments) subsequent to acquisition	6,858

Schedule III - Real Estate and Accumulated Depreciation Properties (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Real Estate and Accumulated Depreciation [Line Items]

Buildings, equipment & improvement, initial cost

2,099,501

Additions (dispositions) (impairments) subsequent to acquisition