Credit Concentration - Schedule of ABR (Annualized Base Rent) (Details) - Sales Revenue, Services, Net $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) Rate
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 299,852
Percent of ABR (annualized base rent) | Rate	100.00%
Customer Concentration Risk | CommonSpirit - CHI - Nebraska
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 16,744
Percent of ABR (annualized base rent)	5.60%
Customer Concentration Risk | CommonSpirit - CHI - KentuckyOne
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 13,956
Percent of ABR (annualized base rent)	4.60%
Customer Concentration Risk | Northside Hospital
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 13,175
Percent of ABR (annualized base rent)	4.40%
Customer Concentration Risk | Baylor Scott and White Health
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 7,770
Percent of ABR (annualized base rent)	2.60%
Customer Concentration Risk | US Oncology
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 7,546
Percent of ABR (annualized base rent)	2.50%
Customer Concentration Risk | Remaining portfolio
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 240,661
Percent of ABR (annualized base rent) | Rate	80.30%
Geographic Concentration Risk | Texas
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 50,603
Percent of ABR (annualized base rent)	16.90%
Geographic Concentration Risk | Georgia
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 25,915
Percent of ABR (annualized base rent)	8.60%
Geographic Concentration Risk | Indiana
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 21,337
Percent of ABR (annualized base rent)	7.10%
Geographic Concentration Risk | Nebraska
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 18,061
Percent of ABR (annualized base rent)	6.00%
Geographic Concentration Risk | Minnesota
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 17,429
Percent of ABR (annualized base rent)	5.80%
Geographic Concentration Risk | Other
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 166,507
Percent of ABR (annualized base rent)	55.60%