Short-term Financing	6 Months Ended
Dec. 31, 2018
Short-Term Financing [Abstract]
Short-Term Financing	Short-term Financing The Company has a $3.8 billion, 364-day credit agreement that matures in June 2019 with a one year term-out option. The Company also has a $2.25 billion five year credit facility that matures in June 2022 that also contains an accordion feature under which the aggregate commitment can be increased by $500 million, subject to the availability of additional commitments. In addition, the Company has a five year $3.75 billion credit facility maturing in June 2023 that contains an accordion feature under which the aggregate commitment can be increased by $500 million, subject to the availability of additional commitments. The interest rate applicable to committed borrowings is tied to LIBOR, the effective federal funds rate, or the prime rate, depending on the notification provided by the Company to the syndicated financial institutions prior to borrowing. The Company is also required to pay facility fees on the credit agreements. The primary uses of the credit facilities are to provide liquidity to the commercial paper program and funding for general corporate purposes, if necessary. The Company had no borrowings through December 31, 2018 under the credit agreements. The Company's U.S. short-term funding requirements related to client funds are sometimes obtained on an unsecured basis through the issuance of commercial paper, rather than liquidating previously-collected client funds that have already been invested in available-for-sale securities. This commercial paper program provides for the issuance of up to $9.8 billion in aggregate maturity value. The Company’s commercial paper program is rated A-1+ by Standard & Poor’s and Prime-1 by Moody’s. These ratings denote the highest quality commercial paper securities. Maturities of commercial paper can range from overnight to up to 364 days. At December 31, 2018, the Company had $1.2 billion of commercial paper outstanding, which was repaid on January 2, 2019. At June 30, 2018, the Company had no commercial paper outstanding. For the three months ended December 31, 2018 and 2017, the Company had average daily borrowings of $3.8 billion and $3.5 billion, respectively, at weighted average interest rates of 2.3% and 1.2%, respectively. For the six months ended December 31, 2018 and 2017, the Company had average daily borrowings of $3.8 billion and $3.7 billion, respectively, at weighted average interest rates of 2.1% and 1.2%, respectively. The weighted average maturity of the Company’s commercial paper during the three and six months ended December 31, 2018 was approximately two days. The Company’s U.S., Canadian and United Kingdom short-term funding requirements related to client funds obligations are sometimes obtained on a secured basis through the use of reverse repurchase agreements, which are collateralized principally by government and government agency securities, rather than liquidating previously-collected client funds that have already been invested in available-for-sale securities. These agreements generally have terms ranging from overnight to up to five business days. At December 31, 2018 and June 30, 2018, there were no outstanding obligations related to reverse repurchase agreements. For the three months ended December 31, 2018 and 2017, the Company had average outstanding balances under reverse repurchase agreements of $325.4 million and $537.0 million, respectively, at weighted average interest rates of 1.9% and 1.2%, respectively. For the six months ended December 31, 2018 and 2017, the Company had average outstanding balances under reverse repurchase agreements of $410.2 million and $531.6 million, respectively, at weighted average interest rates of 1.8% and 1.1%, respectively.

Short-term Financing

The Company has a $3.8 billion, 364-day credit agreement that matures in June 2019 with a one year term-out option. The Company also has a $2.25 billion five year credit facility that matures in June 2022 that also contains an accordion feature under which the aggregate commitment can be increased by $500 million, subject to the availability of additional commitments. In addition, the Company has a five year $3.75 billion credit facility maturing in June 2023 that contains an accordion feature under which the aggregate commitment can be increased by $500 million, subject to the availability of additional commitments. The interest rate applicable to committed borrowings is tied to LIBOR, the effective federal funds rate, or the prime rate, depending on the notification provided by the Company to the syndicated financial institutions prior to borrowing. The Company is also required to pay facility fees on the credit agreements. The primary uses of the credit facilities are to provide liquidity to the commercial paper program and funding for general corporate purposes, if necessary. The Company had no borrowings through December 31, 2018 under the credit agreements.

The Company's U.S. short-term funding requirements related to client funds are sometimes obtained on an unsecured basis through the issuance of commercial paper, rather than liquidating previously-collected client funds that have already been invested in available-for-sale securities. This commercial paper program provides for the issuance of up to $9.8 billion in aggregate maturity value. The Company’s commercial paper program is rated A-1+ by Standard & Poor’s and Prime-1 by Moody’s. These ratings denote the highest quality commercial paper securities. Maturities of commercial paper can range from overnight to up to 364 days. At December 31, 2018, the Company had $1.2 billion of commercial paper outstanding, which was repaid on January 2, 2019. At June 30, 2018, the Company had no commercial paper outstanding. For the three months ended December 31, 2018 and 2017, the Company had average daily borrowings of $3.8 billion and $3.5 billion, respectively, at weighted average interest rates of 2.3% and 1.2%, respectively. For the six months ended December 31, 2018 and 2017, the Company had average daily borrowings of $3.8 billion and $3.7 billion, respectively, at weighted average interest rates of 2.1% and 1.2%, respectively. The weighted average maturity of the Company’s commercial paper during the three and six months ended December 31, 2018 was approximately two days.

The Company’s U.S., Canadian and United Kingdom short-term funding requirements related to client funds obligations are sometimes obtained on a secured basis through the use of reverse repurchase agreements, which are collateralized principally by government and government agency securities, rather than liquidating previously-collected client funds that have already been invested in available-for-sale securities. These agreements generally have terms ranging from overnight to up to five business days. At December 31, 2018 and June 30, 2018, there were no outstanding obligations related to reverse repurchase agreements. For the three months ended December 31, 2018 and 2017, the Company had average outstanding balances under reverse repurchase agreements of $325.4 million and $537.0 million, respectively, at weighted average interest rates of 1.9% and 1.2%, respectively. For the six months ended December 31, 2018 and 2017, the Company had average outstanding balances under reverse repurchase agreements of $410.2 million and $531.6 million, respectively, at weighted average interest rates of 1.8% and 1.1%, respectively.