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Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Retirement Benefits [Abstract]
Employer contribution match, percent match			100.00%
Employer contribution match, percentage of employee contribution			6.00%
Defined contributions plan expense	$ 3	$ 3	$ 10	$ 10
Cost or expenses included in compensation and benefit expense	4	$ 5	$ 15	$ 13
Employer contributions, amount	$ 22
Funded status, percentage	100.00%

X

- Definition

Defined Contribution Plan, Funded Percentage

+ References

No definition available.

+ Details

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X

- References

No definition available.

+ Details

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X

- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

+ Details

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X

- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

+ Details

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X

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

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X

- Definition

Percentage employer matches of the employee's percentage contribution matched.

+ References

No definition available.

+ Details

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X

- Definition

Amount of cost (reversal of cost) for pension and other postretirement benefits.

+ References

No definition available.

+ Details

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