Real Estate Investments - Property Dispositions and Held for Sale Assets Narrative (Details)		3 Months Ended	6 Months Ended
	Jun. 27, 2017 property	Jun. 30, 2017 property	Jun. 30, 2017 USD ($) property	Jun. 30, 2016 USD ($) property
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed | property			1
Number of properties secured by each non-recourse loan | property	4		4
Proceeds after debt assumptions and closing costs			$ 301,320,000	$ 345,251,000
Foreign Tax Authority [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tax provision for the gain on sale of property			$ 1,700,000
Consolidated Property Dispositions, 2017 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed | property			87
Aggregate proceeds			$ 439,200,000
Company's share of proceeds			425,600,000
Proceeds after debt assumptions and closing costs			301,300,000
Debt assumed			66,000,000
Gain related to sale, including goodwill			$ 55,600,000
Red Lobster [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed | property		15	20	24
Consolidated Property Dispositions, 2016 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of real estate properties disposed | property				145
Aggregate proceeds				$ 381,300,000
Company's share of proceeds				368,400,000
Proceeds after debt assumptions and closing costs				303,000,000
Debt assumed				55,000,000
Gain related to sale, including goodwill				22,200,000
Goodwill included in sale				21,500,000
Unconsolidated Property Dispositions, 2016 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Company's share of proceeds				$ 102,100,000
Number of disposed properties owned by unconsolidated joint ventures | property				1
Net proceeds				$ 113,500,000
Proceeds from after debt repayments and closing costs				42,300,000
Debt repayments				57,000,000
Gain related to sale of unconsolidated entities				10,200,000
Property Dispositions, 2017 [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of properties classified held for sale | property		5	5
Net gain (loss) on sale of properties			$ (500,000)
Goodwill allocated to dispositions and held for sale assets			$ 0
2016 Property Dispositions [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain (loss) on sale of properties				(4,600,000)
Goodwill allocated to dispositions and held for sale assets				$ 14,600,000