Business, Basis of Presentation and Significant Accounting Policies Revenue Recognition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Disaggregation of Revenue [Line Items]
Capitalized Contract Cost, Impairment Loss	$ 0
Capitalized Contract Cost, Amortization	18
Capitalized Contract Cost, Net	$ 93
Revenue from contract with customer excluding assessed tax percentage	14.80%
Revenue from Contract with Customer, Excluding Assessed Tax	$ 325
Other assets	251	$ 140
Retained earnings (deficit)	483	30
Operating expenses	647	801	$ 815
Net Cash Provided by (Used in) Operating Activities	1,246	979	$ 2,054
Recordkeeping & administration
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	202
Distribution & shareholder servicing
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	123
Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption		$ 72
Accounts Receivable, Net	$ 63
Maximum
Disaggregation of Revenue [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years
Minimum
Disaggregation of Revenue [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Disaggregation of Revenue [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 72
Other assets	$ 93			90
Deferred Income Tax Liabilities, Net	(20)			$ (18)
Retained earnings (deficit)	73
Operating expenses	3
Net Cash Provided by (Used in) Operating Activities	$ 0