CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 144,019	$ 156,548
Short-term investments	27,183	26,109
Total cash, cash equivalents and short-term investments	171,202	182,657
Settlement assets	139,248	169,327
Trade accounts receivable:
Billed, net of allowance of $4,057 and $3,735	244,413	244,058
Unbilled	35,941	33,450
Income taxes receivable	7,516	4,297
Other current assets	44,448	35,293
Total current assets	642,768	669,082
Non-current assets:
Property and equipment, net of depreciation of $100,883 and $98,029	84,689	84,429
Operating lease right-of-use assets	117,304	94,847
Intangible assets	81,917	87,631
Goodwill	262,774	259,164
Client contract costs, net of amortization of $37,827 and $31,526	41,561	50,746
Deferred income taxes	9,193	9,392
Other assets	29,176	27,739
Total non-current assets	626,614	613,948
Total assets	1,269,382	1,283,030
Current liabilities:
Current portion of long-term debt	12,188	10,313
Operating lease liabilities	21,771	22,442
Client deposits	37,278	38,687
Trade accounts payable	34,494	32,704
Accrued employee compensation	45,689	77,527
Settlement liabilities	137,894	168,342
Deferred revenue	52,195	45,094
Income taxes payable	7,632	2,806
Other current liabilities	21,626	20,778
Total current liabilities	370,767	418,693
Non-current liabilities:
Long-term debt, net of unamortized discounts of $7,726 and $10,053	342,274	346,509
Operating lease liabilities	102,609	78,936
Deferred revenue	16,772	18,552
Income taxes payable	2,706	2,543
Deferred income taxes	13,334	6,376
Other non-current liabilities	23,298	14,759
Total non-current liabilities	500,993	467,675
Total liabilities	871,760	886,368
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; 33,080 and 32,891 shares outstanding	699	696
Additional paid-in capital	458,362	454,663
Treasury stock, at cost; 35,507 and 35,356 shares	(874,592)	(867,817)
Accumulated other comprehensive income (loss):
Unrealized gains on short-term investments, net of tax	44	16
Cumulative foreign currency translation adjustments	(51,932)	(39,519)
Accumulated earnings	865,041	848,623
Total stockholders' equity	397,622	396,662
Total liabilities and stockholders' equity	1,269,382	1,283,030
Software
Non-current assets:
Intangible assets	29,141	32,526
Acquired client contracts
Non-current assets:
Intangible assets	$ 52,776	$ 55,105