Nature of Business and Accounting Policies - Stock-Based Compensation - Improvement (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Jan. 01, 2019
Dec. 31, 2018
Jan. 01, 2018
Jan. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Cumulative effect adjustment for adoption of new accounting guidance   $ 40,310   $ (9,229) $ 0
Deferred tax assets $ 1,190,815 1,510,908 $ 1,499,672    
Accounting standards update 2016-09, excess tax benefit          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Operating loss carryforwards         410,800
Deferred tax assets         3,400
Domestic Tax Authority          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Operating loss carryforwards 1,500,000        
Domestic Tax Authority | Accounting standards update 2016-09, excess tax benefit          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Operating loss carryforwards         404,700
State and Local Jurisdiction          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Operating loss carryforwards $ 903,700        
State and Local Jurisdiction | Accounting standards update 2016-09, excess tax benefit          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Operating loss carryforwards         6,100
Accumulated Deficit          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Cumulative effect adjustment for adoption of new accounting guidance   $ 40,310   $ (33,349) 9,371
Accumulated Deficit | Accounting standards update 2016-09, forfeiture rate component          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Cumulative effect adjustment for adoption of new accounting guidance         $ 9,400