Corporate Investments And Funds Held For Clients (Available-For-Sale Securities That Have Been In An Unrealized Loss Position) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Jun. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	$ (27.9)	$ (34.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,744.3	3,695.3
Fair market value of securities in unrealized loss position less than 12 months	2,623.5	982.1
Fair market value of securities in unrealized loss positions greater than 12 months	2,120.8	2,713.2
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	36.8	38.1
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(8.9)	(3.7)
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(11.7)	(14.1)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,001.1	1,339.8
Fair market value of securities in unrealized loss position less than 12 months	1,165.0	313.8
Fair market value of securities in unrealized loss positions greater than 12 months	836.1	1,026.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	16.5	15.0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(4.8)	(0.9)
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(8.2)	(11.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,139.0	1,029.4
Fair market value of securities in unrealized loss position less than 12 months	492.5	84.6
Fair market value of securities in unrealized loss positions greater than 12 months	646.5	944.8
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	9.5	11.7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1.3)	(0.3)
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(6.7)	(6.2)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,260.7	880.9
Fair market value of securities in unrealized loss position less than 12 months	733.8	325.4
Fair market value of securities in unrealized loss positions greater than 12 months	526.9	555.5
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	8.8	6.9
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(2.1)	(0.7)
Canadian Government Obligations And Canadian Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	43.3	127.2
Fair market value of securities in unrealized loss position less than 12 months	43.3	127.2
Fair market value of securities in unrealized loss positions greater than 12 months	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0	0.8
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	(0.8)
Canadian Provincial Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(0.8)	(1.6)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	166.1	193.8
Fair market value of securities in unrealized loss position less than 12 months	94.6	75.2
Fair market value of securities in unrealized loss positions greater than 12 months	71.5	118.6
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	1.2	2.5
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.4)	(0.9)
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(0.1)	(0.4)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	97.7	64.6
Fair market value of securities in unrealized loss position less than 12 months	88.7	42.0
Fair market value of securities in unrealized loss positions greater than 12 months	9.0	22.6
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0.4	0.5
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(0.3)	(0.1)
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(0.4)	(0.7)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	36.4	59.6
Fair market value of securities in unrealized loss position less than 12 months	5.6	13.9
Fair market value of securities in unrealized loss positions greater than 12 months	30.8	45.7
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	0.4	0.7
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0