Investments (Tables)

12 Months Ended

Sep. 30, 2017

Investments [Abstract]

Investment [Table Text Block]

Our investments consist of (in millions):

	September 30,
	2017		2016
Certificates of deposit and time deposits	$	1,005.3	$	902.8
Commercial paper	20.3		—
Corporate debt securities	199.4		—
Government securities	116.8		—
Asset-backed securities	45.8		—
Total	$	1,387.6	$	902.8

Investments Classified by Contractual Maturity Date [Table Text Block]

The table below summarizes the contractual maturities of our investments as of September 30, 2017 (in millions). Actual maturities may differ from the contractual maturities below as borrowers may have the right to prepay certain obligations.

	Fair Value
Less than one year	$	1,124.6
Due in one to five years	263.0
Total	$	1,387.6

Fair Value, by Balance Sheet Grouping

These investments were included in the following line items within the Consolidated Balance Sheet (in millions):

	September 30,
	2017		2016
Short-term investments	$	1,124.6	$	902.8
Other assets	263.0		—
Total	$	1,387.6	$	902.8

The following table presents the carrying amounts and estimated fair values of financial instruments not measured at fair value in the Consolidated Balance Sheet (in millions):

	September 30, 2017
			Fair Value
	Carrying Amount		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	1,410.9	$	1,410.9	$	1,299.4	$	111.5	$	—
Short-term debt	350.4		350.4		—		350.4		—
Current portion of long-term debt	250.0		251.6		—		251.6		—
Long-term debt	1,243.4		1,452.6		—		1,452.6		—

	September 30, 2016
			Fair Value
	Carrying Amount		Total		Level 1		Level 2		Level 3
Cash and cash equivalents	$	1,526.4	$	1,526.4	$	1,480.6	$	45.8	$	—
Short-term debt	448.6		448.6		—		448.6		—
Current portion of long-term debt	—		—		—		—		—
Long-term debt	1,516.3		1,780.5		—		1,780.5		—