Fair Value Measurements - Narrative (Details) $ in Thousands		6 Months Ended
	Dec. 14, 2018 USD ($)	Jun. 30, 2019 USD ($) loan	Dec. 31, 2018 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payment of earn-out consideration	$ 25,000
Percentage of performance distributions (percent)	37.25%
Common equity invested (percent)	2.50%
Number of mortgage loans (in loan) | loan		6
Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of earn-outs		$ 4,380	$ 29,380