CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 352,921	$ 397,890
Accounts receivable, less allowance for doubtful accounts of $1,900 at September 30, 2018, and $1,747 at September 30, 2017	75,886	64,793
Inventories	71,926	71,873
Prepaid expenses and other current assets	22,048	16,426
Total current assets	522,781	550,982
Property, plant and equipment, net	111,403	106,361
Goodwill	101,083	101,932
Other intangible assets, net	35,202	42,710
Deferred income taxes	5,840	21,598
Other long-term assets	4,664	10,517
Total assets	780,973	834,100
Current liabilities:
Accounts payable	18,171	17,624
Current portion of long-term debt	0	10,938
Accrued expenses, income taxes payable and other current liabilities	82,983	62,651
Total current liabilities	101,154	91,213
Long-term debt, net of current portion, less prepaid debt issuance cost of $441 at September 30, 2017	0	132,997
Deferred income taxes	81	63
Other long-term liabilities	13,046	14,790
Total liabilities	114,281	239,063
Commitments and contingencies (Note 10)
Stockholders' equity:
Common Stock: Authorized: 200,000,000 shares, $0.001 par value; Issued: 35,862,465 shares at September 30, 2018, and 35,230,742 shares at September 30, 2017	36	35
Capital in excess of par value of common stock	622,498	580,938
Retained earnings	471,673	397,881
Accumulated other comprehensive income	4,539	3,949
Treasury stock at cost, 10,356,147 shares at September 30, 2018, and 9,948,190 shares at September 30, 2017	(432,054)	(387,766)
Total stockholders' equity	666,692	595,037
Total liabilities and stockholders' equity	$ 780,973	$ 834,100