UNAUDITED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017
Current assets:
Cash and cash equivalents	$ 377,230	$ 397,890
Available-for-sale securities	48,272	0
Accounts receivable, less allowance for doubtful accounts of $1,785 at December 31, 2017, and $1,747 at September 30, 2017	69,871	64,793
Inventories	73,982	71,873
Prepaid expenses and other current assets	18,688	16,426
Total current assets	588,043	550,982
Property, plant and equipment, net	107,748	106,361
Goodwill	102,740	101,932
Other intangible assets, net	40,742	42,710
Deferred income taxes	7,649	21,598
Other long-term assets	11,077	10,517
Total assets	857,999	834,100
Current liabilities:
Accounts payable	14,974	17,624
Current portion of long-term debt	16,406	10,938
Accrued expenses, income taxes payable and other current liabilities	58,720	62,651
Total current liabilities	90,100	91,213
Long-term debt, net of current portion, less prepaid debt issuance cost of $378 at December 31, 2017 and $441 at September 30, 2017	124,310	132,997
Deferred income taxes	63	63
Other long-term liabilities	41,858	14,790
Total liabilities	256,331	239,063
Commitments and contingencies (Note 10)
Stockholders' equity:
Common Stock: Authorized: 200,000,000 shares, $0.001 par value; Issued: 35,471,403 shares at December 31, 2017, and 35,230,742 shares at September 30, 2017	35	35
Capital in excess of par value of common stock	593,258	580,938
Retained earnings	389,645	397,881
Accumulated other comprehensive income	11,246	3,949
Treasury stock at cost, 9,999,034 shares at December 31, 2017, and 9,948,190 shares at September 30, 2017	(392,516)	(387,766)
Total stockholders' equity	601,668	595,037
Total liabilities and stockholders' equity	$ 857,999	$ 834,100

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.