Unaudited Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 215,093	$ 151,710
Accounts receivable	19,792	9,130
Prepaid expenses	24,109	17,854
Inventory	1,088	1,151
Income tax receivable		10,447
Deferred contract costs	64,441	60,819
Current assets before funds held for clients	324,523	251,111
Funds held for clients	2,299,684	1,613,494
Total current assets	2,624,207	1,864,605
Property and equipment, net	301,579	285,218
Goodwill	51,889	51,889
Long-term deferred contract costs	394,867	371,357
Other assets	34,231	34,843
Total assets	3,406,773	2,607,912
Current liabilities:
Accounts payable	12,133	6,787
Income tax payable	12,977
Accrued commissions and bonuses	6,781	13,703
Accrued payroll and vacation	32,634	24,529
Deferred revenue	14,191	13,567
Current portion of long-term debt	1,775	1,775
Accrued expenses and other current liabilities	45,399	44,175
Current liabilities before client funds obligation	125,890	104,536
Client funds obligation	2,299,684	1,613,494
Total current liabilities	2,425,574	1,718,030
Deferred income tax liabilities, net	115,336	112,598
Long-term deferred revenue	74,802	73,259
Net long-term debt, less current portion	28,684	29,119
Other long-term liabilities	16,901	19,263
Total long-term liabilities	235,723	234,239
Total liabilities	2,661,297	1,952,269
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value (100,000 shares authorized, 61,864 and 61,861 shares issued at March 31, 2021 and December 31, 2020, respectively; 57,741 and 57,739 shares outstanding at March 31, 2021 and December 31, 2020, respectively)	618	618
Additional paid-in capital	383,502	357,908
Retained earnings	784,235	719,619
Treasury stock, at cost (4,123 and 4,122 shares at March 31, 2021 and December 31, 2020, respectively)	(422,879)	(422,502)
Total stockholders' equity	745,476	655,643
Total liabilities and stockholders' equity	$ 3,406,773	$ 2,607,912