Quarterly Financial Data (Unaudited) - Narrative (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||
---|---|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Quarterly Financial Information Disclosure [Abstract] | |||||
Asset impairment charges | $ 49,400 | $ 58,100 | $ 49,375 | $ 58,057 | $ 7,964 |
Asset impairment charges, net of tax | 36,500 | $ 36,600 | |||
Net tax charges related to final assessment of the Tax Act | $ 36,000 |