Summary of Significant Accounting Policies (Tables)

12 Months Ended

Sep. 30, 2018


Buildings		10 - 40 years
Computer equipment and software		3 - 7 years
Machinery and equipment		2 - 10 years
Furniture and fixtures		3 - 10 years

Summary of Amortizable Lives of Intangible Assets


Patents		7 - 15 years
Completed technology		3 - 10 years
Customer relationships		3 - 11 years

Stock-Based Compensation Expense

The following table reflects stock-based compensation expense, excluding amounts related to discontinued operations, recorded during the fiscal years ended September 30, 2018, 2017 and 2016 (in thousands):


	Year Ended September 30,
	2018		2017		2016
Restricted stock	$	18,081	$	16,056	$	10,859
Employee stock purchase plan		775		517		418
Total stock-based compensation expense	$	18,856	$	16,573	$	11,277

Fair Value of Shares Issued under Employee Stock Purchase Plan Estimated using Black-Scholes Option Pricing Model


	Year Ended September 30,
	2018		2017		2016
Risk-free interest rate	1.9	%	0.9	%	0.4	%
Volatility	46	%	34	%	32	%
Expected life	6 months		6 months		6 months
Dividend yield	1.5	%	3.4	%	3.4	%