Stock-based Compensation (Tables)

6 Months Ended

Mar. 31, 2019

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Fair Value of Stock Options, Black-Scholes Option-Pricing Model, Weighted-Average Assumptions

The fair value of the stock options granted during the six months ended March 31, 2019 were estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions:

Risk-free interest rate	3.00	%
Expected volatility	29.35	%
Expected life (in years)	5.18
Dividend yield	-

Stock Options Outstanding and Activity During the Period

The following table summarizes all stock option activity for the six months ended March 31, 2019 (in thousands, except share, per share, and time period amounts):

	Options Outstanding			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (Years)		Aggregate Intrinsic Value1
Balance as of September 30, 2018		1,969,037		$	33.08		5.7	$	14,088
Granted		611,031			27.31
Exercised		(87,554	)		17.80
Canceled/Forfeited		(40,525	)		39.22
Expired		(950	)		12.25
Balance as of March 31, 2019		2,451,039		$	32.10		6.4	$	11,615
Vested and expected to vest after March 31, 2019		2,402,609		$	32.09		6.3	$	11,424
Exercisable as of March 31, 2019		1,586,518		$	30.88		4.9	$	8,462

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¹ Aggregate intrinsic value represents the difference between the closing fair value of the underlying common stock and the exercise price of outstanding, in-the-money options on the date of measurement.

Stock Option Grants, Vesting, and Exercises

The following table summarizes additional information on stock options for the periods presented (in thousands, except per share amounts):

	Six Months Ended March 31,
	2019		2018
Weighted-average fair value of stock options granted	$	8.77	$	15.86
Total grant date fair value of stock options vested		3,735		3,832
Total intrinsic value of stock options exercised		1,360		7,700

Restricted Shares and Units Outstanding and Activity During the Period

The following table summarizes all restricted stock unit activity for the six months ended March 31, 2019:

	RSUs Outstanding			Weighted-Average Grant Date Fair Value
Balance as of September 30, 2018		934,023		$	47.00
Granted		669,579			27.77
Released		(371,189	)		40.63
Canceled/Forfeited		(86,445	)		46.88
Balance as of March 31, 2019		1,145,968		$	37.83
Vested and expected to vest after March 31, 2019		1,072,948		$	37.62

Schedule Of Restricted Stock Units Additional Information

The following table summarizes additional information on RSUs for the periods presented (in thousands, except per share amounts):

	Six Months Ended March 31,
	2019		2018
Weighted-average fair value of RSUs granted	$	27.77	$	57.40
Total grant date fair value of RSUs vested		15,920		6,523
Total intrinsic value of RSUs released		11,319		10,924