Related Party Transactions (Details)	Jun. 30, 2018	Aug. 07, 2012
ARC | Everest Hill Group | Everest Hill Group
Related party transactions
Percentage ownership by related party	52.70%
QMI | Everest Hill Group | Everest Hill Group
Related party transactions
Percentage ownership by related party	100.00%
QMT | QMI
Related party transactions
Percentage ownership of membership interests		74.00%