Marketable Securities (Tables)

6 Months Ended

Mar. 31, 2012

Summary of Marketable Securities Including Accrued Interest Receivable

The following is a summary of marketable securities (included in short and long-term marketable securities in the consolidated balance sheets), including accrued interest receivable, as of March 31, 2012 and September 30, 2011 (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
March 31, 2012:
U.S. Treasury securities and obligations of U.S. government agencies	$	28,644	$	16	$	(9	)	$	28,651
Corporate securities		67,286		128		(36	)		67,378
Mortgage-backed securities(1)		1,485		35		(7	)		1,513
Other debt securities		413		—		—			413
Municipal securities		22,840		26		(1	)		22,865
Bank certificate of deposits		2,295		1		—			2,296
	$	122,963	$	206	$	(53	)	$	123,116
September 30, 2011:
U.S. Treasury securities and obligations of U.S. government agencies	$	53,342	$	17	$	(21	)	$	53,338
Corporate securities		66,045		50		(203	)		65,892
Mortgage-backed securities(1)		786		26		(3	)		809
Other debt securities		434		—		—			434
Municipal securities		24,915		9		(67	)		24,857
Bank certificate of deposits		1,655		—		—			1,655
	$	147,177	$	102	$	(294	)	$	146,985

(1) Fair value amounts include approximately $0.7 million of investments in the Federal Home Loan Mortgage and Federal National Mortgage Association.

Fair Value of Marketable Securities by Contractual Maturity

The fair value of the marketable securities at March 31, 2012 by contractual maturity, are shown below. Expected maturities will differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties (in thousands).

	Fair Value
Due in one year or less	$	71,057
Due after one year through five years		48,071
Due after ten years		3,988
	$	123,116