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