Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 245,064	$ 409,632
Marketable securities	55,129	76,344
Accounts receivable and unbilled costs, net of allowance for doubtful accounts of $2,280 and $1,583 at September 30, 2019 and March 31, 2019, respectively	202,288	235,318
Inventories and deferred costs	26,195	26,270
Prepaid income taxes	13,109	18,000
Prepaid expenses and other current assets	31,209	35,658
Total current assets	572,994	801,222
Fixed assets, net	58,505	58,951
Operating lease right-of-use assets	65,118
Goodwill	1,719,362	1,715,485
Intangible assets, net	624,799	669,118
Deferred income taxes	7,006	7,218
Long-term marketable securities	7,630	1,012
Other assets	13,960	16,988
Total assets	3,069,374	3,269,994
Current liabilities:
Accounts payable	34,855	24,582
Accrued compensation	50,202	58,501
Accrued other	19,223	23,027
Income taxes payable	1,517	1,318
Deferred revenue and customer deposits	234,229	272,508
Current portion of operating lease liabilities	10,533
Total current liabilities	350,559	379,936
Other long-term liabilities	7,199	19,493
Deferred tax liability	120,895	124,229
Accrued long-term retirement benefits	35,332	36,284
Long-term deferred revenue and customer deposits	97,013	94,619
Operating lease liabilities, net of current portion	68,112
Long-term debt	450,000	550,000
Total liabilities	1,129,110	1,204,561
Commitments and contingencies (Note 14)
Preferred stock, $0.001 par value:
5,000,000 shares authorized; no shares issued or outstanding at September 30, 2019 and March 31, 2019	0	0
Common stock, $0.001 par value:
300,000,000 shares authorized; 121,648,747 and 119,760,132 shares issued and 74,838,047 and 77,610,361 shares outstanding at September 30, 2019 and March 31, 2019, respectively	122	120
Additional paid-in capital	2,863,003	2,828,922
Accumulated other comprehensive loss	(3,699)	(2,639)
Treasury stock at cost, 46,810,700 and 42,149,771 shares at September 30, 2019 and March 31, 2019, respectively	(1,230,440)	(1,119,063)
Retained earnings	311,278	358,093
Total stockholders' equity	1,940,264	2,065,433
Total liabilities and stockholders' equity	$ 3,069,374	$ 3,269,994