Income Taxes - Additional Information (Details) - USD ($)		12 Months Ended
	Jan. 01, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Net increase to valuation allowance primarily due to additional net operating losses		$ 6,800,000	$ 15,500,000	$ 22,400,000
Previously unrecognized excess tax benefit	$ 39,400,000		39,400,000
Undistributed foreign earnings		3,300,000	4,000,000
Potential tax impact if undistributed foreign earnings were distributed		100,000	$ 800,000
Transition tax on undistributed earnings		0
Reduction in tax expense if unrecognized tax benefits are recognized		1,300,000
Decrease in unrecognized tax benefits and income tax due to resolution		1,100,000
Federal Tax Authority
Operating Loss Carryforwards [Line Items]
Federal, state and foreign net operating losses		250,700,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Federal, state and foreign net operating losses		257,900,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Federal, state and foreign net operating losses		$ 86,000,000