Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 91,307	$ 45,718
Accounts receivable	3,835	3,414
Prepaid expenses	9,156	7,658
Inventory	910	797
Income tax receivable		3,962
Deferred contract costs	38,811	35,286
Current assets before funds held for clients	144,019	96,835
Funds held for clients	1,405,465	967,787
Total current assets	1,549,484	1,064,622
Property and equipment, net	187,511	176,962
Goodwill	51,889	51,889
Long-term deferred contract costs	247,135	225,459
Other assets	26,809	2,994
Total assets	2,062,828	1,521,926
Current liabilities:
Accounts payable	4,081	6,288
Income tax payable	3,526
Accrued commissions and bonuses	4,553	10,671
Accrued payroll and vacation	14,506	10,741
Deferred revenue	9,672	8,980
Current portion of long-term debt	1,775	1,775
Accrued expenses and other current liabilities	40,132	22,440
Current liabilities before client funds obligation	78,245	60,895
Client funds obligation	1,405,465	967,787
Total current liabilities	1,483,710	1,028,682
Deferred income tax liabilities, net	73,928	70,206
Long-term deferred revenue	57,839	55,671
Net long-term debt, less current portion	32,179	32,614
Other long-term liabilities	16,619
Total long-term liabilities	180,565	158,491
Total liabilities	1,664,275	1,187,173
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value (100,000,000 shares authorized, 61,027,123 and 60,746,715 shares issued at March 31, 2019 and December 31, 2018, respectively; 57,447,346 and 57,276,992 shares outstanding at March 31, 2019 and December 31, 2018, respectively)	609	607
Additional paid-in capital	239,865	203,680
Retained earnings	442,872	395,590
Treasury stock, at cost (3,579,777 and 3,469,723 shares at March 31, 2019 and December 31, 2018, respectively)	(284,793)	(265,124)
Total stockholders' equity	398,553	334,753
Total liabilities and stockholders' equity	$ 2,062,828	$ 1,521,926