CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 197,172	$ 122,243
Short-term investments	2,130	139,117
Total cash, cash equivalents and short-term investments	199,302	261,360
Trade accounts receivable:
Billed, net of allowance of $4,182 and $4,149	246,731	219,531
Unbilled	36,847	31,187
Income taxes receivable	7,452	13,839
Other current assets	38,706	28,349
Total current assets	529,038	554,266
Non-current assets:
Property and equipment, net of depreciation of $108,266 and $123,126	78,265	44,651
Intangible assets	71,816
Goodwill	210,697	210,080
Client contract costs, net of amortization of $37,038 and zero	35,584
Deferred income taxes	11,011	14,057
Other assets	10,898	10,948
Total non-current assets	418,271	350,268
Total assets	947,309	904,534
Current liabilities:
Current portion of long-term debt	7,500	22,500
Client deposits	36,079	31,053
Trade accounts payable	39,054	38,420
Accrued employee compensation	56,578	62,984
Deferred revenue	41,388	41,885
Income taxes payable	448	1,216
Other current liabilities	21,590	24,535
Total current liabilities	202,637	222,593
Non-current liabilities:
Long-term debt, net of unamortized discounts of $15,641 and $18,264	353,109	309,236
Deferred revenue	13,578	12,346
Income taxes payable	2,372	2,415
Deferred income taxes	5,881	4,584
Other non-current liabilities	11,313	10,614
Total non-current liabilities	386,253	339,195
Total liabilities	588,890	561,788
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; 33,451 and 33,516 shares outstanding	693	689
Common stock warrants; 439 warrants vested; 1,425 issued	9,082	9,082
Additional paid-in capital	436,412	427,091
Treasury stock, at cost; 34,470 and 34,075 shares	(831,585)	(814,732)
Accumulated other comprehensive income (loss):
Unrealized loss on short-term investments, net of tax	(7)	(88)
Cumulative foreign currency translation adjustments	(37,364)	(28,734)
Accumulated earnings	781,188	749,438
Total stockholders' equity	358,419	342,746
Total liabilities and stockholders' equity	947,309	904,534
Software
Non-current assets:
Intangible assets	31,953	26,906
Client contracts
Non-current assets:
Intangible assets		$ 43,626
Acquired client contracts
Non-current assets:
Intangible assets	$ 39,863