FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENT (Tables)

12 Months Ended

Sep. 30, 2017

FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENT

Summary of available-for-sale securities

			Gross		Gross		Estimated
			Unrealized		Unrealized		Fair
	Cost		Gains		Losses		Value
	(in thousands)
Equity Securities:
September 30, 2017	$	38,473	$	31,700	$	—	$	70,173
September 30, 2016	$	38,473	$	33,051	$	—	$	71,524

Summary of assets measured at fair value on a recurring basis

	Fair Value		(Level 1)		(Level 2)		(Level 3)
	(in thousands)
Recurring fair value measurements:
Short-term investments:
Certificates of deposit	$	1,500	$	—	$	1,500	$	—
Corporate and municipal debt securities		15,818		—		15,818		—
U.S. government and federal agency securities		27,173		24,853		2,320		—
Total short-term investments		44,491		24,853		19,638		—
Cash and cash equivalents		521,375		521,375		—		—
Investments		70,173		70,173		—		—
Other current assets		32,439		32,189		250		—
Other assets		6,695		6,695		—		—
Total assets measured at fair value	$	675,173	$	655,285	$	19,888	$	—
Liabilities:
Contingent earnout liability	$	14,879	$	—	$	—	$	14,879

Summary of supplemental fair value information about long-term fixed-rate debt

	September 30,
	2017		2016
	(in millions)
Carrying value of long-term fixed-rate debt	$	492.9	$	491.8
Fair value of long-term fixed-rate debt	$	529.0	$	529.6