Real Estate Properties - Allocation of Purchase Price (Details) $ in Thousands																		12 Months Ended
	Oct. 09, 2019 USD ($) room	Sep. 20, 2019 USD ($) retail_property state	Aug. 01, 2019 USD ($)	May 07, 2019 USD ($) room	Feb. 22, 2019 USD ($) room	Oct. 30, 2018 USD ($) suite	Jun. 15, 2018 USD ($) room suite	Sep. 28, 2017 USD ($)	Sep. 26, 2017 USD ($) hotel state suite	Sep. 08, 2017 USD ($)	Aug. 23, 2017 USD ($) room	Aug. 01, 2017 USD ($) room	Jun. 29, 2017 USD ($) room	Jun. 02, 2017 USD ($) room	May 03, 2017 USD ($)	Mar. 31, 2017 USD ($) room	Feb. 01, 2017 USD ($) room	Dec. 31, 2019 USD ($) state room	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jan. 31, 2019 state
Real Estate Properties [Line Items]
Purchase Price		$ 2,482,382																$ 2,711,985	$ 127,597	$ 606,397
Land																		444,260	10,888	104,548
Land Improvements																		1,204	1,006	15,339
Building and Improvements																		1,365,525	107,128	448,531
Furniture, Fixtures and Equipment																		8,593	8,575	35,296
Held For Sale																		604,989	0	0
Intangible Assets																		$ 287,414	$ 0	$ 2,683
Acquisition costs capitalized		$ 15,736
Number of properties acquired | retail_property		767
Number of states in which property is located | state		45																12
Hotel
Real Estate Properties [Line Items]
Number of rooms/suites | room																		51,349
Net Lease | Travel Centers of America LLC
Real Estate Properties [Line Items]
Number of states in which property is located | state																					15
Washington, DC | Hotel Palomar | Hotel
Real Estate Properties [Line Items]
Purchase Price					$ 143,742
Land					44,972
Land Improvements					151
Building and Improvements					93,412
Furniture, Fixtures and Equipment					5,207
Held For Sale					0
Intangible Assets					$ 0
Number of rooms/suites | room					335,000
Acquisition costs capitalized					$ 2,292
Milwaukee, WI | Crowne Plaza Hotels | Hotel
Real Estate Properties [Line Items]
Purchase Price				$ 30,235
Land				3,442
Land Improvements				1,053
Building and Improvements				25,132
Furniture, Fixtures and Equipment				608
Held For Sale				0
Intangible Assets				$ 0
Number of rooms/suites | room				198,000
Acquisition costs capitalized				$ 235
Southington, CT | Travel Centers of America LLC
Real Estate Properties [Line Items]
Purchase Price			$ 66
Land			66
Land Improvements			0
Building and Improvements			0
Furniture, Fixtures and Equipment			0
Held For Sale			0
Intangible Assets			0
Acquisition costs capitalized			$ 6
Various | Net Lease
Real Estate Properties [Line Items]
Purchase Price		$ 2,482,382
Land		388,057
Land Improvements		0
Building and Improvements		1,201,922
Furniture, Fixtures and Equipment		0
Held For Sale		604,989
Intangible Assets		$ 287,414
Various | Sonesta ES Suites | Hotel
Real Estate Properties [Line Items]
Purchase Price									$ 139,923
Land									30,720
Land Improvements									6,392
Building and Improvements									93,899
Furniture, Fixtures and Equipment									8,912
Held For Sale									0
Intangible Assets									$ 0
Number of rooms/suites | suite									1,653
Acquisition costs capitalized									$ 1,923
Number of properties acquired | hotel									14
Number of states in which property is located | state									12
Minneapolis, MN | Radisson Blu Hotel | Hotel
Real Estate Properties [Line Items]
Purchase Price							$ 75,576
Land							2,196
Land Improvements							0
Building and Improvements							68,388
Furniture, Fixtures and Equipment							4,992
Held For Sale							0
Intangible Assets							$ 0
Number of rooms/suites | room							360
Acquisition costs capitalized							$ 576
Baton Rouge, LA | Staybridge Suites | Hotel
Real Estate Properties [Line Items]
Purchase Price							16,022
Land							2,242
Land Improvements							173
Building and Improvements							12,842
Furniture, Fixtures and Equipment							765
Held For Sale							0
Intangible Assets							$ 0
Number of rooms/suites | suite							117
Acquisition costs capitalized							$ 272
Scottsdale, AZ | Hotel
Real Estate Properties [Line Items]
Purchase Price						$ 35,999
Land						6,450
Land Improvements						833
Building and Improvements						25,898
Furniture, Fixtures and Equipment						2,818
Held For Sale						0
Intangible Assets						$ 0
Number of rooms/suites | suite						164
Acquisition costs capitalized						$ 114
Chicago, IL | Hotel Palomar | Hotel
Real Estate Properties [Line Items]
Purchase Price	$ 55,560
Land	7,723
Land Improvements	0
Building and Improvements	45,059
Furniture, Fixtures and Equipment	2,778
Held For Sale	0
Intangible Assets	$ 0
Number of rooms/suites | room	261,000
Acquisition costs capitalized	$ 560
Chicago, IL | Hotel Allegro | Hotel
Real Estate Properties [Line Items]
Purchase Price																	$ 86,201
Land																	13,609
Land Improvements																	40
Building and Improvements																	58,929
Furniture, Fixtures and Equipment																	11,926
Held For Sale																	0
Intangible Assets																	$ 1,697
Number of rooms/suites | room																	483
Acquisition costs capitalized																	$ 707
Seattle, WA | Hotel Alexis | Hotel
Real Estate Properties [Line Items]
Purchase Price																$ 73,041
Land																24,562
Land Improvements																30
Building and Improvements																47,103
Furniture, Fixtures and Equipment																898
Held For Sale																0
Intangible Assets																$ 448
Number of rooms/suites | room																121
Acquisition costs capitalized																$ 1,416
Columbia, SC | Net Lease | Travel Centers of America LLC
Real Estate Properties [Line Items]
Purchase Price															$ 27,604
Land															4,040
Land Improvements															7,172
Building and Improvements															16,392
Furniture, Fixtures and Equipment															0
Held For Sale															0
Intangible Assets															$ 0
St. Louis, MO | Chase Park Plaza Hotel | Hotel | Sonesta
Real Estate Properties [Line Items]
Purchase Price														$ 88,080
Land														4,250
Land Improvements														161
Building and Improvements														79,737
Furniture, Fixtures and Equipment														3,394
Held For Sale														0
Intangible Assets														$ 538
Number of rooms/suites | room														389
Acquisition costs capitalized														$ 466
Atlanta, GA | Crowne Plaza Hotels
Real Estate Properties [Line Items]
Purchase Price										$ 940
Land										940
Land Improvements										0
Building and Improvements										0
Furniture, Fixtures and Equipment										0
Held For Sale										0
Intangible Assets										0
Acquisition costs capitalized										$ 40
Atlanta, GA | Crowne Plaza Ravinia | Hotel
Real Estate Properties [Line Items]
Purchase Price													$ 88,748
Land													16,612
Land Improvements													483
Building and Improvements													68,864
Furniture, Fixtures and Equipment													2,789
Held For Sale													0
Intangible Assets													$ 0
Number of rooms/suites | room													495
Acquisition costs capitalized													$ 144
Columbus, OH | Crowne Plaza & Lofts Hotel | Hotel
Real Estate Properties [Line Items]
Purchase Price												$ 49,188
Land												6,100
Land Improvements												49
Building and Improvements												40,678
Furniture, Fixtures and Equipment												2,361
Held For Sale												0
Intangible Assets												$ 0
Number of rooms/suites | room												419
Acquisition costs capitalized												$ 198
Charlotte, NC | Crowne Plaza Hotels | Hotel
Real Estate Properties [Line Items]
Purchase Price											$ 44,000
Land											2,684
Land Improvements											1,012
Building and Improvements											35,288
Furniture, Fixtures and Equipment											5,016
Held For Sale											0
Intangible Assets											$ 0
Number of rooms/suites | room											300
Acquisition costs capitalized											$ 143
Sayre, OK | Net Lease | Travel Centers of America LLC
Real Estate Properties [Line Items]
Purchase Price								$ 8,672
Land								1,031
Land Improvements								0
Building and Improvements								7,641
Furniture, Fixtures and Equipment								0
Held For Sale								0
Intangible Assets								0
Acquisition costs capitalized								$ 72