CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 156,548	$ 139,277
Short-term investments	26,109	23,603
Total cash, cash equivalents and short-term investments	182,657	162,880
Settlement assets	169,327	124,627
Trade accounts receivable:
Billed, net of allowance of $3,735 and $3,115	244,058	235,827
Unbilled	33,450	37,227
Income taxes receivable	4,297	6,720
Other current assets	35,293	32,286
Total current assets	669,082	599,567
Non-current assets:
Property and equipment, net of depreciation of $98,029 and $93,278	84,429	81,813
Operating lease right-of-use assets	94,847
Intangible assets	32,526	36,400
Goodwill	259,164	255,816
Client contract costs, net of amortization of $31,526 and $43,051	50,746	37,289
Deferred income taxes	9,392	11,087
Other assets	27,739	26,934
Total non-current assets	613,948	514,795
Total assets	1,283,030	1,114,362
Current liabilities:
Current portion of long-term debt	10,313	7,500
Operating lease liabilities	22,442
Client deposits	38,687	36,889
Trade accounts payable	32,704	45,386
Accrued employee compensation	77,527	61,107
Settlement liabilities	168,342	123,613
Deferred revenue	45,094	40,236
Income taxes payable	2,806	218
Other current liabilities	20,778	35,442
Total current liabilities	418,693	350,391
Non-current liabilities:
Long-term debt, net of unamortized discounts of $10,053 and $14,549	346,509	352,326
Operating lease liabilities	78,936
Deferred revenue	18,552	17,527
Income taxes payable	2,543	2,284
Deferred income taxes	6,376	8,205
Other non-current liabilities	14,759	22,605
Total non-current liabilities	467,675	402,947
Total liabilities	886,368	753,338
Stockholders' equity:
Preferred stock, par value $.01 per share; 10,000 shares authorized; zero shares issued and outstanding
Common stock, par value $.01 per share; 100,000 shares authorized; 3,661 and 4,460 shares reserved for employee stock purchase plan and stock incentive plans; 32,891 and 33,158 shares outstanding	696	693
Common stock warrants; zero and 439 warrants vested; 950 and 1,425 issued		9,082
Additional paid-in capital	454,663	441,417
Treasury stock, at cost; 35,356 and 34,779 shares	(867,817)	(842,360)
Accumulated other comprehensive income (loss):
Unrealized gains on short-term investments, net of tax	16	2
Cumulative foreign currency translation adjustments	(39,519)	(42,937)
Accumulated earnings	848,623	795,127
Total stockholders' equity	396,662	361,024
Total liabilities and stockholders' equity	1,283,030	1,114,362
Software
Non-current assets:
Intangible assets	32,526	36,400
Acquired client contracts
Non-current assets:
Intangible assets	$ 55,105	$ 65,456