Restructuring - Summary of Restructuring Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring costs	$ 112,184	$ 0	$ 0
Special termination costs	42,757	$ 0	$ 0
Total costs incurred in 2019	154,941
Remaining costs expected but not yet incurred	20,331
Total costs	$ 175,272