Commitments and Contingencies - Litigation (Details)		9 Months Ended	12 Months Ended
	Sep. 27, 2016 USD ($)	Sep. 30, 2017 item	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)
Commitments and Contingencies
Number of claims | item		2
Insurance proceeds			$ 187,500
Paid legal award	$ (2,375,000)		$ (950,000)
Amount paid not covered by insurance	$ 0
Outstanding settlement amount				$ 2,355,000