Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 90	$ 94	$ 98
Liability for deferred compensation plans	163	189
Defined Benefit Plan, Noncash Settlement Loss	2	6
Trading Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Liability for deferred compensation plans	32	37
Company-Owned Life Insurance Contracts [Member]
Defined Benefit Plan Disclosure [Line Items]
Liability for deferred compensation plans	114	136
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected contribution by employer	1
Net periodic benefit cost	1	7	1
Accrued benefits liabilities	$ 11	12
Defined benefit plans and other post-retirement plans, weighted-average assumptions to determine net periodic cost, discount rate	3.60%
Defined benefit plans and other post-retirement plans, weighted-average assumptions to determine net periodic cost, rate of compensation increase	6.50%
Trust for Benefit of Employees [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan assets designated to pay benefits of the deferred compensation plans	$ 146	173
Unfunded Supplemental Employee Retirement Plan (SERP) [Member]
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	9	16	$ 12
Accrued benefits liabilities	$ 66	83
Defined benefit plans and other post-retirement plans, weighted-average assumptions to determine net periodic cost, discount rate	3.40%
Defined benefit plans and other post-retirement plans, weighted-average assumptions to determine net periodic cost, rate of compensation increase	2.00%
Assets in a rabbi trust generally designated to pay benefits of the SERP	$ 74	$ 99