CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Trade accounts receivable-billed, allowance	$ 2,736	$ 2,359
Property and equipment, accumulated depreciation	135,483	129,522
Accumulated amortization	170,660	152,886
Long-term debt, unamortized original issue discount	15,656	19,950
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
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	100,000
Common stock, shares outstanding	34,527	33,745
Treasury stock, shares	32,222	32,030
Software
Accumulated amortization	85,209	77,504
Client contracts
Accumulated amortization	$ 85,451	$ 75,382