Real Estate Investments (Schedule of Assets Acquired and Liabilities Assumed) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) property	Dec. 31, 2018 USD ($) property	Dec. 31, 2017 USD ($) property
Real estate investments, at cost:
Land	$ 76,610	$ 61,745	$ 313,423
Buildings, fixtures and improvements	288,549	140,151	1,176,909
Total tangible assets	365,159	201,896	1,490,332
Acquired intangible assets and liabilities
Acquired intangibles	63,780	39,876	94,806
Above-market ground lease liability	0	0	0
Below-market lease liabilities	(4,980)	(1,157)	(106,513)
Prior Credit Facility assumed in the Merger	0	0	(304,000)
Mortgage notes payable assumed in the Merger	0	0	(127,651)
Premiums on mortgage notes payable assumed in the Merger	0	0	(4,143)
Other assets acquired and (liabilities assumed) in the Merger, net	0	0	16,427
Consideration paid for acquired real estate investments, net of liabilities assumed	$ 428,939	$ 241,772	$ 1,165,771
Number of properties purchased | property	218	130	110
In-place leases
Acquired intangible assets and liabilities
Acquired intangibles	$ 66,787	$ 39,978	$ 177,152
Weighted-average amortization period	14 years 8 months 12 days
Above-market lease assets
Acquired intangible assets and liabilities
Acquired intangibles	$ 1,973	1,055	22,934
Weighted-average amortization period	11 years 7 months 6 days
Below-market ground lease asset
Acquired intangible assets and liabilities
Acquired intangibles	$ 0	$ 0	$ 1,233
Below-market lease liabilities
Acquired intangible assets and liabilities
Weighted-average amortization period	16 years 9 months 18 days