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	6 Months Ended	12 Months Ended
	Dec. 31, 2013	Jun. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	$ (115.7)	$ (131.1)
Fair market value of securities in unrealized loss position less than 12 months	5,988.6	6,142.0
Unrealized losses greater than 12 months	(13.2)
Fair market value of securities in unrealized loss positions greater than 12 months	309.2
Total available for sale securities - Unrealized Loss	(128.9)	(131.1)
Total fair market value of securities in unrealized loss position	6,297.8	6,142.0
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(52.0)	(56.7)
Fair market value of securities in unrealized loss position less than 12 months	2,465.3	2,724.9
Unrealized losses greater than 12 months	(2.7)
Fair market value of securities in unrealized loss positions greater than 12 months	45.8
Total available for sale securities - Unrealized Loss	(54.7)	(56.7)
Total fair market value of securities in unrealized loss position	2,511.1	2,724.9
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(33.0)	(37.4)
Fair market value of securities in unrealized loss position less than 12 months	1,464.4	1,374.6
Unrealized losses greater than 12 months	(7.8)
Fair market value of securities in unrealized loss positions greater than 12 months	215.7
Total available for sale securities - Unrealized Loss	(40.8)	(37.4)
Total fair market value of securities in unrealized loss position	1,680.1	1,374.6
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(14.6)	(19.7)
Fair market value of securities in unrealized loss position less than 12 months	1,146.3	1,060.1
Unrealized losses greater than 12 months	(1.2)
Fair market value of securities in unrealized loss positions greater than 12 months	24.7
Total available for sale securities - Unrealized Loss	(15.8)	(19.7)
Total fair market value of securities in unrealized loss position	1,171.0	1,060.1
Canadian Government Obligations And Canadian Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(3.4)	(4.5)
Fair market value of securities in unrealized loss position less than 12 months	394.9	444.7
Unrealized losses greater than 12 months	0
Fair market value of securities in unrealized loss positions greater than 12 months	0
Total available for sale securities - Unrealized Loss	(3.4)	(4.5)
Total fair market value of securities in unrealized loss position	394.9	444.7
Canadian Provincial Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(6.0)	(5.6)
Fair market value of securities in unrealized loss position less than 12 months	227.9	239.7
Unrealized losses greater than 12 months	(1.0)
Fair market value of securities in unrealized loss positions greater than 12 months	9.0
Total available for sale securities - Unrealized Loss	(7.0)	(5.6)
Total fair market value of securities in unrealized loss position	236.9	239.7
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(3.1)	(4.4)
Fair market value of securities in unrealized loss position less than 12 months	151.4	188.7
Unrealized losses greater than 12 months	(0.5)
Fair market value of securities in unrealized loss positions greater than 12 months	13.7
Total available for sale securities - Unrealized Loss	(3.6)	(4.4)
Total fair market value of securities in unrealized loss position	165.1	188.7
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unrealized losses less than 12 months	(3.6)	(2.8)
Fair market value of securities in unrealized loss position less than 12 months	138.4	109.3
Unrealized losses greater than 12 months	0
Fair market value of securities in unrealized loss positions greater than 12 months	0.3
Total available for sale securities - Unrealized Loss	(3.6)	(2.8)
Total fair market value of securities in unrealized loss position	$ 138.7	$ 109.3