Related Party Transactions - QIA (Details) - Q REIT Holding LLC $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Noncontrolling Interest [Line Items]
Minimum interest required to be held by affiliate of QIA in order to purchase new equity securities	5.00%
Threshold of equity securities issuance where top up rights are exercisable	$ 1.0
Right to first offer to co-invest, period (in months)	30 months
Term for JV (in years)	5 years
Extended term (in months)	30 months
Threshold to indemnify	10.00%