Summary of Significant Accounting Policies Accounts Payable (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Accounts Payable	$ 127	$ 116
Accrued Salaries, Current	48	58
Supplemental Unemployment Benefits, Severance Benefits	4	6
Taxes Payable, Current	7	4
Accrued Exchange Fee Rebate, Current	34	30
Operating Lease, Liability, Current	8	0
Other Accrued Liabilities, Current	14	20
Accounts payable and accrued liabilities	242	234
Capital Expenditures Incurred but Not yet Paid	$ 15	$ 22

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for rebates of an exchange fee some mutual funds impose on shareholders if they exchange (transfer) to another fund within the same fund group. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of the obligations incurred through that date and payable for employees' services provided. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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Amount of expenses incurred but not yet paid classified as other.

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Liability for amount due employees, in addition to wages and any other money that employers owe employees, when their employment ends through a layoff or other termination. For example, a company may provide involuntarily terminated employees with a lump sum payment equal to one week's salary for every year of employment.

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Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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