UNAUDITED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2018	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 186,124	$ 397,890
Available-for-sale securities	124,455	0
Accounts receivable, less allowance for doubtful accounts of $1,817 at June 30, 2018, and $1,747 at September 30, 2017	74,017	64,793
Inventories	77,302	71,873
Prepaid expenses and other current assets	29,008	16,426
Total current assets	490,906	550,982
Property, plant and equipment, net	108,569	106,361
Goodwill	101,059	101,932
Other intangible assets, net	36,982	42,710
Deferred income taxes	13,067	21,598
Other long-term assets	8,899	10,517
Total assets	759,482	834,100
Current liabilities:
Accounts payable	18,290	17,624
Current portion of long-term debt	0	10,938
Accrued expenses, income taxes payable and other current liabilities	72,009	62,651
Total current liabilities	90,299	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	62	63
Other long-term liabilities	34,940	14,790
Total liabilities	125,301	239,063
Commitments and contingencies (Note 10)
Stockholders' equity:
Common Stock: Authorized: 200,000,000 shares, $0.001 par value; Issued: 35,806,136 shares at June 30, 2018, and 35,230,742 shares at September 30, 2017	36	35
Capital in excess of par value of common stock	615,543	580,938
Retained earnings	433,818	397,881
Accumulated other comprehensive income	6,114	3,949
Treasury stock at cost, 10,262,236 shares at June 30, 2018, and 9,948,190 shares at September 30, 2017	(421,330)	(387,766)
Total stockholders' equity	634,181	595,037
Total liabilities and stockholders' equity	$ 759,482	$ 834,100