Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions		12 Months Ended
	Jul. 29, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Servicing Asset, Measurement Input		$ 0
Business Combination, Contingent Consideration, Liability		43
Liability [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability, Current		23
Paid [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability		$ 20
Lattice
Business Acquisition [Line Items]
Contingent consideration	$ 60
Contingent consideration period	4 years
Lattice | Contingent Consideration
Business Acquisition [Line Items]
Discount rate		11.80%
Fair Value Measured at Net Asset Value Per Share [Member]
Business Acquisition [Line Items]
Deposit Assets		$ 38	$ 0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Contingent Consideration
Business Acquisition [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value		22	$ 35	$ 29
AUM Value [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input [Extensible List]		3,300
Forecast [Member] | AUM Value [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability, Measurement Input [Extensible List]		$ 4,100