Income Taxes - Operating Loss Carryforwards (Details) - USD ($) $ in Thousands |
Dec. 31, 2018 |
Dec. 31, 2017 |
---|---|---|
Internal Revenue Service (IRS) [Member] | ||
Operating Loss Carryforwards [Line Items] | ||
Loss carryforwards | $ 1,048,000 | |
Foreign Tax Authority [Member] | ||
Operating Loss Carryforwards [Line Items] | ||
Operating loss carryforwards subject to expiration | 150,600 | |
Operating loss carryforwards not subject to expiration | 897,500 | |
State and Local Jurisdiction [Member] | ||
Operating Loss Carryforwards [Line Items] | ||
Loss carryforwards | $ 62,900 | $ 59,800 |