Consolidated Statements Of Income and Comprehensive Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Service revenue	$ 2,117.6	$ 2,094.3	$ 2,016.0
Reimbursement revenue	323.9	332.0	314.3
Total revenue	2,441.5	2,426.3	2,330.3
Costs and expenses:
Direct costs	1,377.5	1,360.3	1,344.2
Reimbursable out-of-pocket expenses	323.9	332.0	314.3
Selling, general and administrative	401.3	385.3	367.2
Depreciation	78.7	74.6	69.3
Amortization	27.7	22.3	15.6
Restructuring charge	41.2	27.8	19.8
Total costs and expenses	2,250.3	2,202.3	2,130.4
Income from operations	191.2	224.0	199.9
Interest expense, net	(12.3)	(8.6)	(7.1)
Miscellaneous expense, net	(22.7)	(0.2)	7.4
Total other expense, net	(35.0)	(8.8)	0.3
Income before provision for income taxes	156.2	215.2	200.2
Provision for income taxes	48.9	60.3	52.4
Net income	$ 107.3	$ 154.9	$ 147.8
Earnings per share:
Basic	$ 2.08	$ 2.90	$ 2.69
Diluted	$ 2.06	$ 2.86	$ 2.65
Weighted average shares:
Basic	51.5	53.5	54.9
Diluted	52.2	54.2	55.8
Statement of Comprehensive Income [Abstract]
Net income	$ 107.3	$ 154.9	$ 147.8
Unrealized gain (loss) on derivative instruments, net of taxes	8.6	(5.8)	(3.9)
Foreign currency translation adjustment	7.2	(34.3)	(94.1)
Total comprehensive income	$ 123.1	$ 114.8	$ 49.8