Credit Concentration - Schedule of ABR (Annualized Base Rent) (Details) - Sales Revenue, Services, Net $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) Rate
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 291,126
Percent of ABR (annualized base rent) | Rate	100.00%
Customer Concentration Risk | CommonSpirit - CHI - Nebraska
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 16,683
Percent of ABR (annualized base rent)	5.70%
Customer Concentration Risk | CommonSpirit - CHI - KentuckyOne
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 13,907
Percent of ABR (annualized base rent)	4.80%
Customer Concentration Risk | Northside Hospital
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 10,253
Percent of ABR (annualized base rent)	3.50%
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)	2.70%
Customer Concentration Risk | Ascension - St. Vincent's - Indianapolis
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 7,384
Percent of ABR (annualized base rent)	2.50%
Customer Concentration Risk | Remaining portfolio
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 235,129
Percent of ABR (annualized base rent) | Rate	80.80%
Geographic Concentration Risk | Texas
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 46,537
Percent of ABR (annualized base rent)	16.00%
Geographic Concentration Risk | Georgia
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 25,558
Percent of ABR (annualized base rent)	8.80%
Geographic Concentration Risk | Indiana
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 20,037
Percent of ABR (annualized base rent)	6.90%
Geographic Concentration Risk | Nebraska
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 17,982
Percent of ABR (annualized base rent)	6.20%
Geographic Concentration Risk | Minnesota
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 17,285
Percent of ABR (annualized base rent)	5.90%
Geographic Concentration Risk | Other
Concentration Risk [Line Items]
Total ABR (annualized base rent)	$ 163,727
Percent of ABR (annualized base rent)	56.20%