Income Taxes - Operating Loss Carryforwards (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Operating loss carryforwards disclosures
Increase in valuation allowance	$ 50.5
Tax effect of amortization of intangible assets not expected to reverse within the Company's net operating loss carryforward period	13.2
Capital losses
Operating loss carryforwards disclosures
Tax credit carry forwards	3.5
Federal
Operating loss carryforwards disclosures
Net operating loss carryforwards	137.2
Federal | Research and development tax credit carryforward
Operating loss carryforwards disclosures
Tax credit carry forwards	12.1
State and local
Operating loss carryforwards disclosures
Net operating loss carryforwards	68.0
Tax credit carry forwards	9.9
Net deferred tax asset	3.5
Foreign
Operating loss carryforwards disclosures
Tax credit carry forwards	$ 7.7