Consolidated Statements Of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 33.0	$ 28.8	$ 80.6	$ 45.8
Other comprehensive income (loss), net of tax
Pension and post-retirement benefits, net of tax of $(1.2), $(2.8), $(3.7), and $(8.0), respectively	2.0	4.3	6.0	13.1
Net (loss) gain on derivative instruments, net of tax of $3.1, $(0.8), $18.3, and $(10.8), respectively	(4.9)	1.3	(29.9)	17.9
Unrealized gain (loss) on marketable securities, net of tax of $0.0, $0.0, $1.0, and $0.0, respectively		0.1	(0.2)
Foreign currency translation	6.5	7.2	(10.0)	14.7
Other comprehensive income (loss)	3.6	12.9	(34.1)	45.7
Comprehensive income	36.6	41.7	46.5	91.5
Less: Comprehensive income attributable to the noncontrolling interest	(0.3)	(0.4)	0.6	(0.6)
Comprehensive income attributable to Carpenter	$ 36.3	$ 41.3	$ 47.1	$ 90.9