Employee Benefit Plans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Purchase price of common stock as percentage of market value			95.00%
Shares repurchased	0.9	1.1	6.2	2.4
Vesting term of performance-based restricted stock, months			approximately 18 months
Total stock-based compensation expense	$ 27.2	$ 22.8	$ 45.7	$ 36.7
Total stock-based compensation - related tax benefits	10.0	8.5	16.8	13.7
Compensation expense recognition			Compensation expense is recognized on a straight-line basis over the vesting period
Employer contributions			79.2
Expected future employer contribution	4.8		4.8
Stock Options Granted Prior To July 2008 [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock options - term in years for stock options granted prior to July 1, 2008			10
Length of vesting rate for options granted prior to July 1, 2008 (in years)			five
Stock options - term in years for stock options granted after July 1, 2008			10
Stock Options Granted After July 2008 [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock options - term in years for stock options granted prior to July 1, 2008			10
Stock options - term in years for stock options granted after July 1, 2008			10
Length of vesting rate for options granted after July 1, 2008 (in years)			four
Time-Based Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Transfer period restriction			5
Performance-Based Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Minimum percentage that will ultimately vest under performance-based restricted stock awards based on performance target			0.00%
Maximum percentage that will ultimately vest under performance-based restricted stock awards based on performance target			150.00%
Performance period, years			1
Service period, months			6
Non-Vested Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total remaining unrecognized compensation cost	5.4		5.4
Amortization period for total remaining unrecognized compensation cost (in years)			1.3
Non-Vested Restricted Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total remaining unrecognized compensation cost	$ 70.3		$ 70.3
Amortization period for total remaining unrecognized compensation cost (in years)			1.3