Cabot Transaction - Summary (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 24, 2018	Dec. 31, 2018
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Change Due to Net Income Attributable to Parent and Effects of Changes, Net [Abstract]
Total reduction in additional paid-in capital		$ 43,097
Cabot Holdings
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Change Due to Net Income Attributable to Parent and Effects of Changes, Net [Abstract]
Cash consideration	$ 234,101
Stock consideration	180,559
Total consideration transferred	414,660
Less: Preferred equity certificates acquired	(262,512)
Consideration transferred to acquire remaining equity interest	152,148
Less: Carrying value of redeemable noncontrolling interest	(127,299)
Less: Carrying value of noncontrolling interest	9,626
Net loss directly recorded in equity	34,475
Direct and incremental transaction costs	8,622
Total reduction in additional paid-in capital	$ 43,097