Goodwill and Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2015	Sep. 30, 2018
Goodwill
Goodwill			$ 104,600	$ 104,587
Intangible assets acquired			33,100
Changes in carrying amount of goodwill
Goodwill, Beginning Balance				104,587
Goodwill impairment	$ (29,925)	$ (74,700)		$ (104,587)
Goodwill, Ending Balance			104,600
Trademark
Goodwill
Intangible assets acquired			17,200
Customer relationships
Goodwill
Intangible assets acquired			10,200
Non-compete agreement
Goodwill
Intangible assets acquired			$ 5,700