Noncontrolling Interest (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Noncontrolling Interest [Abstract]
Common stock, conversion term		6 months
Common stock, conversion basis (in shares)		1
Operating Trust
Noncontrolling Interest [Line Items]
Noncontrolling interest, weighted average ownership percentage by parent	99.96%	99.97%