Stockholders' Equity (Tables)

12 Months Ended

Sep. 30, 2017

Information related to the equity incentive plans as of the fiscal year end is as follows:

	2017					2016
	Number of Shares (in thousands)			Weighted Average Exercise Price		Number of Shares (in thousands)			Weighted Average Exercise Price
Options outstanding, beginning of period		11,716		$	21.44		11,351		$	17.71
Options granted		1,820			49.53		2,805			30.27
Options exercised		(2,562	)		12.07		(2,061	)		12.57
Options forfeited or cancelled		(214	)		33.52		(379	)		23.37
Options outstanding, end of period		10,760		$	28.18		11,716		$	21.44

Option price range at end of period	$	3.04-49.53				$	3.04-45.62
Options exercisable at end of period		4,108					4,573
Options available for grant at period end		2,875					4,695
Weighted average fair value of options granted during period	$	15.52				$	8.68

Valuation Assumptions Used for Options Granted

The fair value for options granted has been estimated at the date of grant using a Black-Scholes model, generally with the following weighted average assumptions:

	2017			2016			2015
Risk-free interest rate		2.2	%		1.2	%		1.6	%
Dividend yield		0.00	%		0.00	%		0.00	%
Volatility factor		.26			.26			.30
Expected option life	7 years			7 years			7 years

Options Outstanding

The following table summarizes information about the options outstanding as of fiscal 2017:

Range of Exercise Prices				Number Outstanding (in thousands)				Intrinsic Value of Outstanding (in millions)			Weighted Remaining Contractual Life		Weighted Exercise Price				Number Exercisable (in thousands)				Intrinsic Value of Exercisable (in millions)				Unrecognized Compensation (in millions)			Weighted Recognition Period
$	3.04-49.53				10,760			$	306		7 years		$	28.18				4,108			$	146			$	35		2 years