CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Trade accounts receivable-billed, allowance	$ 2,706	$ 3,080
Property and equipment, accumulated depreciation	129,475	122,866
Accumulated amortization	192,658	196,039
Current portion of long-term debt, unamortized discounts	0	296
Long-term debt, unamortized discounts	$ 20,652	$ 23,007
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	33,700,000	32,261,000
Common stock warrants, vested	0	1,426,000
Common stock warrants, issued	1,425,000	2,851,000
Treasury stock, shares	33,830,000	34,919,000
Software
Accumulated amortization	$ 104,252	$ 99,316
Client contracts
Accumulated amortization	$ 88,406	$ 96,723