Costs Associated With Restructuring Activities - Additional Information (Details) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Restructuring and Related Activities [Abstract] | |||
| Restructuring charges | $ 0 | $ 0 | $ 6,341,000 |
| Total restructuring costs incurred to date | $ 20,500,000 | ||