CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017
Current assets
Cash and cash equivalents	$ 202,339	$ 101,622
Marketable securities	15,658	28
Accounts receivable, net	139,047	120,828
Inventories	115,033	106,395
Prepaid expenses and other current assets	24,782	23,138
Total current assets	496,859	352,011
Property, plant and equipment, net	60,294	58,462
Long-term marketable securities	13,885	2,642
Long-term deferred tax assets	1,642	1,692
Goodwill	272,724	233,638
Intangible assets, net	105,757	83,520
Equity method investment	30,925	28,593
Other assets	5,591	6,070
Total assets	987,677	766,628
Current liabilities
Current portion of long term debt	1,993
Accounts payable	54,242	49,100
Deferred revenue	25,701	24,292
Accrued warranty and retrofit costs	8,218	8,054
Accrued compensation and benefits	16,027	27,065
Accrued restructuring costs	1,127	1,708
Accrued income taxes payable	15,120	11,417
Accrued expenses and other current liabilities	26,977	25,142
Total current liabilities	149,405	146,778
Long-term debt	195,276
Long-term tax reserves	1,412	1,687
Long-term deferred tax liabilities	8,290	3,748
Long-term pension liabilities	1,995	1,979
Other long-term liabilities	5,295	4,792
Total liabilities	361,673	158,984
Commitments and contingencies (Note 16)
Stockholders' Equity
Preferred stock, $0.01 par value- 1,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.01 par value- 125,000,000 shares authorized, 83,891,452 shares issued and 70,429,583 shares outstanding at December 31, 2017, 83,294,848 shares issued and 69,832,979 shares outstanding at September 30, 2017	839	833
Additional paid-in capital	1,879,721	1,874,918
Accumulated other comprehensive income	19,335	15,213
Treasury stock, at cost- 13,461,869 shares	(200,956)	(200,956)
Accumulated deficit	(1,072,935)	(1,082,364)
Total stockholders' equity	626,004	607,644
Total liabilities and stockholders' equity	$ 987,677	$ 766,628