Corporate Investments And Funds Held For Clients (Corporate Investments And Funds Held For Clients) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Jun. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Money market securities and other cash equivalents - Amortized Cost	$ 13,907.9	$ 9,731.8
Money market securities and other cash equivalents - Gross Unrealized Gains
Money market securities and other cash equivalents -Gross Unrealized Losses
Money market securities and other cash equivalents - Fair Value	13,907.9	9,731.8
Total available-for-sale securities - Amortized Cost	17,058.9	16,356.6
Total available-for-sale securities - Gross Unrealized Gains	673.1	605.5
Total available-for-sale securities - Gross Unrealized Losses	(13.1)	(34.6)
Total available-for-sale securities - Fair Value	17,718.9	16,927.5
Total corporate investments and funds held for clients - Amortized Cost	30,966.8	26,088.4
Total corporate investments and funds held for clients - Gross Unrealized Gains	673.1	605.5
Total corporate investments and funds held for clients - Gross Unrealized Losses	(13.1)	(34.6)
Total corporate investments and funds held for clients - Fair Value	31,626.8	26,659.3
U.S. Treasury And Direct Obligations Of U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	6,439.3	6,558.2
Total available-for-sale securities - Gross Unrealized Gains	247.3	213.0
Total available-for-sale securities - Gross Unrealized Losses	(3.0)	(12.1)
Total available-for-sale securities - Fair Value	6,683.6	6,759.1
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	6,898.0	5,908.6
Total available-for-sale securities - Gross Unrealized Gains	252.5	234.9
Total available-for-sale securities - Gross Unrealized Losses	(7.6)	(16.9)
Total available-for-sale securities - Fair Value	7,142.9	6,126.6
Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	398.3	422.4
Total available-for-sale securities - Gross Unrealized Gains	16.3	25.4
Total available-for-sale securities - Gross Unrealized Losses	(0.2)
Total available-for-sale securities - Fair Value	414.4	447.8
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	324.4	476.6
Total available-for-sale securities - Gross Unrealized Gains	12.8	15.9
Total available-for-sale securities - Gross Unrealized Losses
Total available-for-sale securities - Fair Value	337.2	492.5
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	509.6	493.7
Total available-for-sale securities - Gross Unrealized Gains	30.1	23.1
Total available-for-sale securities - Gross Unrealized Losses	(0.4)	(0.6)
Total available-for-sale securities - Fair Value	539.3	516.2
Canadian Government Obligations And Canadian Government Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	1,021.7	1,082.0
Total available-for-sale securities - Gross Unrealized Gains	22.1	20.8
Total available-for-sale securities - Gross Unrealized Losses	(0.5)	(1.3)
Total available-for-sale securities - Fair Value	1,043.3	1,101.5
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Total available-for-sale securities - Amortized Cost	1,467.6	1,415.1
Total available-for-sale securities - Gross Unrealized Gains	92.0	72.4
Total available-for-sale securities - Gross Unrealized Losses	(1.4)	(3.7)
Total available-for-sale securities - Fair Value	$ 1,558.2	$ 1,483.8