Real Estate Investments (Details) $ in Thousands, ft² in Millions	12 Months Ended
Dec. 31, 2018 USD ($) ft² site	Dec. 31, 2017 USD ($) ft²	Dec. 31, 2016 USD ($)
Real Estate Properties [Line Items]
Number of Real Estate Properties	645	436
Net Rentable Area \| ft²	11.2	8.7
Real Estate Investment Property, Net, Total	$ 1,661,334	$ 1,214,016
Deferred Revenue	4,627	1,837
Operating Leases, Rent Expense	645	653	$ 653
Proceeds from Sale of Real Estate	65,800	44,300	27,900
Gains (Losses) on Sales of Investment Real Estate	11,200	14,200	10,000
Provision for impairment	$ (2,319)	$ 0	$ 0
Sixteen Development And Pcs Projects [Member]
Real Estate Properties [Line Items]
Number of Development and Partner Capital Solutions Projects Construction \| site	16
2018 Business Acquisition [Member]
Real Estate Properties [Line Items]
Retail Net Lease Assets Purchased	225
Contingent consideration	$ 0
2018 Business Acquisition [Member] \| Two Hundred Twenty Five Retail Net Lease Assets [Member]
Real Estate Properties [Line Items]
Payments to Acquire Property, Plant, and Equipment	$ 608,300
Number Of States Properties Located	37
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (in year)	12 years 4 months 24 days
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land	$ 164,700
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings	325,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	118,600
2017 Business Acquisition [Member]
Real Estate Properties [Line Items]
Retail Net Lease Assets Purchased		79
Contingent consideration		$ 0
2017 Business Acquisition [Member] \| Seventy Nine Retail Net Lease Assets [Member]
Real Estate Properties [Line Items]
Payments to Acquire Property, Plant, and Equipment		$ 338,000
Number Of States Properties Located		27
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (in year)		11 years 1 month 6 days
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Land		$ 94,100
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Buildings		172,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 71,900
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt	$ 21,500

The number of Development and Partner Capital Solutions projects being constructed or beginning construction.

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Amount of facility held for productive use including, but not limited to, office, production, storage and distribution facilities, acquired at the acquisition date.

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Amount of real estate acquired, at the acquisition date.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

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The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

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Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Net rentable area for properties owned.

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The number of real estate properties owned as of the balance sheet date.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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Cash received for the sale of real estate that is not part of an investing activity during the current period.

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Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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