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Summary of Significant Accounting Policies ASU Adjustment (Details) - USD ($) |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jan. 01, 2019 | Dec. 31, 2019 | Dec. 31, 2018 | Jan. 01, 2018 | Dec. 31, 2017 | Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |
Retained Earnings (Accumulated Deficit) |  |  | $ 967,587,000 | $ 1,165,842,000 |  |  |  |
Deferred Tax Assets, Net of Valuation Allowance |  |  | 32,649,000 | $ 34,875,000 |  |  |  |
Right-of-use assets obtained in exchange for new operating lease liabilities |  |  | 25,360,000 |  |  |  |  |
Cumulative effect of accounting change | [1] |  |  |  | $ 0 |  |  | $ 44,732,000
ASU 2016-09 Cumulative Effect Adjustment for Timing of Recognition of Excess Tax Benefits [Member] |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |
Retained Earnings (Accumulated Deficit) |  |  |  |  |  |  |  | 44,300,000
ASU 2016-09 Cumulative Effect of Actual Forfeiture Rate [Member] |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |
Retained Earnings (Accumulated Deficit) |  |  |  |  |  |  |  | (700,000)
Additional Paid in Capital |  |  |  |  |  |  |  | 1,100,000
Deferred Tax Assets, Net of Valuation Allowance |  |  |  |  |  |  |  | $ (400,000)
Accounting Standards Update 2016-02 [Member] |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |
Right-of-use assets obtained in exchange for new operating lease liabilities |  | $ 50,000,000.0 |  |  |  |  |  |
Accounting Standards Update 2018-02 [Member] |  |  |  |  |  |  |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |  |  |  |  |  |  |
Cumulative effect of accounting change |  |  | $ 0 |  | $ 2,969,000 | [2] | $ 0 |
[1] | (1) Please refer to Recently Issued Accounting Standards in Note 1 – Summary of Significant Accounting Policies for additional information.
[2] | (1) Please refer to Recently Issued Accounting Standards in Note 1 – Summary of Significant Accounting Policies and Statements of Stockholders’ Equity for additional information.

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