Fair Value Measurements (Tables)

9 Months Ended

Jun. 30, 2018

Fair Value Disclosures [Abstract]

Schedule of Financial Assets Measured at Fair Value on a Recurring Basis

The Company’s financial assets measured at fair value on a recurring basis subject to the disclosure requirements at June 30, 2018, were as follows (in thousands):

	Fair Value Measurements at Reporting Date Using
	Quoted Prices in Active Markets for Identical Securities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at June 30, 2018
Cash equivalents	$	22,626	$	3,644	$	—	$	26,270
Short-term investments
Available-for-sale securities — certificates of deposits	—		1,742		—		1,742
Available-for-sale securities — corporate bonds and notes	—		266,082		—		266,082
Available-for-sale securities — municipal bonds and notes	—		41,044		—		41,044
Available-for-sale securities — U.S. government securities	—		107,319		—		107,319
Available-for-sale securities — U.S. government agency securities	—		69,045		—		69,045
Long-term investments
Available-for-sale securities — corporate bonds and notes	—		269,842		—		269,842
Available-for-sale securities — municipal bonds and notes	—		21,168		—		21,168
Available-for-sale securities — U.S. government securities	—		18,195		—		18,195
Available-for-sale securities — U.S. government agency securities	—		20,207		—		20,207
Total	$	22,626	$	818,288	$	—	$	840,914

The Company’s financial assets measured at fair value on a recurring basis subject to the disclosure requirements at September 30, 2017, were as follows (in thousands):

	Fair Value Measurements at Reporting Date Using
	Quoted Prices in Active Markets for Identical Securities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Fair Value at September 30, 2017
Cash equivalents	$	13,967	$	3,192	$	—	$	17,159
Short-term investments
Available-for-sale securities — corporate bonds and notes	—		172,493		—		172,493
Available-for-sale securities — municipal bonds and notes	—		67,409		—		67,409
Available-for-sale securities — U.S. government securities	—		72,930		—		72,930
Available-for-sale securities — U.S. government agency securities	—		30,868		—		30,868
Long-term investments
Available-for-sale securities — corporate bonds and notes	—		191,782		—		191,782
Available-for-sale securities — municipal bonds and notes	—		26,643		—		26,643
Available-for-sale securities — U.S. government securities	—		29,374		—		29,374
Available-for-sale securities — U.S. government agency securities	—		37,003		—		37,003
Total	$	13,967	$	631,694	$	—	$	645,661