Income Taxes - Narrative (Details)	3 Months Ended			12 Months Ended			101 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2014 USD ($) ownership	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Aug. 31, 2006 USD ($)
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits	$ 1,132,000			$ 1,248,000	$ 1,132,000	$ 1,019,000	$ 1,019,000	$ 899,000
Number of changes in ownership | ownership							3
Valuation allowance	96,298,000			112,322,000	96,298,000
Income tax expense				(948,000)	(15,901,000)	84,000
Penalties and interest expense				0	0	0
Penalties and interest accrued	0			0	0
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Net operating losses				208,935,000
Tax credit carryforward, amount				3,022,000
Operating loss carryforwards decrease									$ 121,100,000	$ 1,900,000
Tax credit carryforwards, decrease									3,017,000	$ 8,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount				3,648,000
Operating loss carryforwards decrease									$ 53,329,000
State and Local Jurisdiction [Member] | California [Member]
Operating Loss Carryforwards [Line Items]
Net operating losses				191,267,000
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating losses				63,546,000
Zohydro ER [Member]
Operating Loss Carryforwards [Line Items]
Tax effect of sale of discontinued operation	$ (3,472,000)	$ (5,496,000)	$ (6,946,000)	88,000	14,060,000	0
Zogenix Europe Limited [Member]
Operating Loss Carryforwards [Line Items]
Income tax expense				52,000	45,000	84,000
Zogenix International Limited [Member]
Operating Loss Carryforwards [Line Items]
Income tax expense				$ (1,000,000)	$ (2,100,000)	$ 0