Restructuring Activities and Charges - Narrative (Details) $ in Thousands			3 Months Ended	9 Months Ended	12 Months Ended			17 Months Ended
	Feb. 21, 2019	Dec. 14, 2015 USD ($) employee	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Feb. 24, 2020 USD ($)	Aug. 10, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, extension period	2 years
Restructuring charges			$ 2,892	$ 10,524	$ 15,918	$ 6,031	$ 0
Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Non-cash settlements / adjustments										$ 400
Restructuring charges					15,918	6,031		$ 21,900
Restructuring Plan, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 6,700
Expected number of positions eliminated | employee		100
Employee Severance and Related Benefits | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges					5,073	3,257
Employee Severance and Related Benefits | Restructuring Plan, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 5,600
Lease and Contract Termination Costs | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges					920	512
Lease and Contract Termination Costs | Restructuring Plan, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 1,100
Compensation Realignment and Other Retention | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges					$ 5,208	$ 0
Minimum | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost										20,000
Maximum | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost										$ 25,000
Subsequent Event | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Non-cash settlements / adjustments									$ 500
Subsequent Event | Minimum | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									35,000
Subsequent Event | Minimum | Employee Severance and Related Benefits | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									9,000
Subsequent Event | Minimum | Lease and Contract Termination Costs | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									8,000
Subsequent Event | Minimum | Compensation Realignment and Other Retention | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									18,000
Subsequent Event | Maximum | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									45,000
Subsequent Event | Maximum | Employee Severance and Related Benefits | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									12,000
Subsequent Event | Maximum | Lease and Contract Termination Costs | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									10,000
Subsequent Event | Maximum | Compensation Realignment and Other Retention | Restructuring Plan, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges, expected cost									$ 23,000