Stock-based Compensation - Management Unit Awards - Activity (Details) - Management Unit Awards	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Units
Unvested at the beginning of the period (in shares) | shares	90,762
Vested (in shares) | shares	(45,381)
Unvested at the end of the period (in shares) | shares	45,381
Weighted Average Grant Date Fair Value per Share
Unvested at the beginning of the period (in dollars per share) | $ / shares	$ 15.00
Vested (in dollars per share) | $ / shares	15.00
Unvested at the end of the period (in dollars per share) | $ / shares	$ 15.00