Rent and Tenant Receivables and Other Assets, Net (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Accounts receivable, net	$ 49,148,000	$ 44,798,000
Straight-line rent receivable	201,584,000	161,079,000
Deferred costs, net	16,154,000	26,110,000
Prepaid expenses	6,814,000	9,773,000
Leasehold improvements, property and equipment, net	14,702,000	18,180,000
Restricted escrow deposits	5,741,000	1,190,000
Deferred tax asset and tax receivable	31,113,000	25,287,000
Program development costs, net	3,161,000	12,855,000
Interest rate swap assets, at fair value	199,000	1,892,000
Other assets, net	2,089,000	2,473,000
Total	330,705,000	303,637,000
Allowance for doubtful accounts	6,000,000	6,600,000
Reserve for interest receivables	1,600,000	0
Rent and Tenant Receivables and Other Assets, Net [Member] | Program Development Costs [Member]
Property, Plant and Equipment [Line Items]
Reserves related to program development costs	31,700,000	34,800,000
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Amortization expense	2,300,000	2,200,000	$ 1,300,000
Amortization write off	1,000,000
Accumulated amortization and depreciation	3,500,000	2,600,000
Property and Equipment [Member]
Property, Plant and Equipment [Line Items]
Accumulated amortization and depreciation	3,900,000	3,700,000
Depreciation expense	3,400,000	2,100,000	1,600,000
Depreciation write off	1,200,000
Line of Credit [Member]
Property, Plant and Equipment [Line Items]
Amortization expense	10,400,000	10,700,000	$ 10,800,000
Accumulated amortization for deferred costs	$ 29,800,000	$ 19,400,000