Performance Bonds and Guaranty Fund Contributions (Details) $ in Billions |
9 Months Ended |
---|---|
Sep. 30, 2019
USD ($)
| |
Guarantor Obligations [Line Items] | |
Average Daily Clearing Settlement | $ 3.5 |
Federal Reserve Reinvestment [Member] | |
Guarantor Obligations [Line Items] | |
Cash Equivalents, at Carrying Value | 26.0 |
U.S. Treasury Performance Bond [Member] | |
Guarantor Obligations [Line Items] | |
Available-for-sale Securities, Amortized Cost Basis | 1.4 |
Available-for-sale Securities at Fair Value | 1.4 |
U.S. Government Agency Security Performance Bond [Member] | |
Guarantor Obligations [Line Items] | |
Available-for-sale Securities, Amortized Cost Basis | 0.5 |
Available-for-sale Securities at Fair Value | $ 0.5 |