CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 107,422	$ 126,351
Short-term investments	130,450	150,147
Total cash, cash equivalents and short-term investments	237,872	276,498
Trade accounts receivable:
Billed, net of allowance of $2,824 and $3,080	195,311	208,930
Unbilled	40,191	30,828
Income taxes receivable	17,874	11,931
Other current assets	29,270	31,751
Total current assets	520,518	559,938
Non-current assets:
Property and equipment, net of depreciation of $126,230 and $122,866	36,418	33,116
Intangible assets	68,017	71,102
Goodwill	202,750	201,094
Deferred income taxes	12,328	14,218
Other assets	12,371	12,411
Total non-current assets	331,884	331,941
Total assets	852,402	891,879
Current liabilities:
Current portion of long-term debt, net of unamortized discounts of zero and $296	16,875	49,426
Client deposits	33,006	33,916
Trade accounts payable	31,803	35,118
Accrued employee compensation	48,716	65,341
Deferred revenue	50,435	45,064
Income taxes payable	547	822
Other current liabilities	18,897	22,342
Total current liabilities	200,279	252,029
Non-current liabilities:
Long-term debt, net of unamortized discounts of $21,834 and $23,007	322,541	326,993
Deferred revenue	7,595	6,694
Income taxes payable	2,405	2,245
Deferred income taxes	3,643	99
Other non-current liabilities	12,208	12,618
Total non-current liabilities	348,392	348,649
Total liabilities	548,671	600,678
Current portion of long-term debt conversion obligation		39,841
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; 33,825 and 32,261 shares outstanding	689	672
Common stock warrants; zero and 1,426 warrants vested; 1,425 and 2,851 issued		16,007
Additional paid-in capital	415,450	391,209
Treasury stock, at cost; 33,702 and 34,919 shares	(799,605)	(826,002)
Accumulated other comprehensive income (loss):
Unrealized loss on short-term investments, net of tax	(115)	(159)
Cumulative foreign currency translation adjustments	(40,874)	(45,213)
Accumulated earnings	728,186	714,846
Total stockholders' equity	303,731	251,360
Total liabilities, current portion of long-term debt conversion obligation and stockholders' equity	852,402	891,879
Software
Non-current assets:
Intangible assets	29,451	30,427
Client contracts
Non-current assets:
Intangible assets	$ 38,566	$ 40,675