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Income Taxes - Additional Information (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Operating Loss Carryforwards [Line Items] |  |  |
Federal statutory income tax rate | 34.00% | 34.00% | 34.00%
Increase (decrease) in the valuation allowance | $ 19,600,000 | $ 29,900,000 | $ (73,900,000)
Unrecognized Tax Benefits that Would Impact Effective Tax Rate | 8,000,000 |  |
Unrecognized tax benefits, income tax penalties or interest charged | 0 |  |
Stock Option [Member] |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Net Operating Loss Carry-forwards | 5,200,000 |  |
State [Member] |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Net Operating Loss Carry-forwards | 202,700,000 |  |
California [Member] |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Net operating loss carry-forward expired | 22,400,000 | 54,300,000 | 16,800,000
Federal [Member] |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Net Operating Loss Carry-forwards | 311,500,000 |  |
Net operating loss carry-forward expired | $ 0 | $ 0 | $ 0

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- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319 + Details
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