Fair Value Measurements - Additional Disclosures (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Cash and cash equivalents	$ 106,994,000			$ 106,994,000		$ 3,044,000
Cash equivalents	57,700,000			57,700,000		0
Interest bearing demand deposit	45,500,000			45,500,000
Cash	3,800,000			3,800,000		$ 3,000,000.0
Assets Measured at Fair Value on a Nonrecurring Basis [Line Items]
Impairment of goodwill	$ 0	$ 0		$ 0	$ 37,180,000
Energy Chemistry Technologies
Assets Measured at Fair Value on a Nonrecurring Basis [Line Items]
Impairment of goodwill			$ 37,200,000