Commitments and Contingencies - Narrative (Details) - Rochester, New Hampshire - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2019	Mar. 31, 2017	Dec. 31, 2018
Loss Contingencies [Line Items]
Expense associated with expected costs of site investigation	$ 300,000	$ 200,000	$ 100,000
Capital expenditures			200,000
Environmental Contamination
Loss Contingencies [Line Items]
Accrual for environmental liability, including revision (fully offset)			$ 0