Condensed Consolidated Balance Sheets - Unaudited (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Statement - Condensed Consolidated Balance Sheets - Unaudited (Parenthetical) [Line Items]
Trade accounts receivable-billed, allowance	$ 3,618	$ 3,147
Property and equipment, net of depreciation	125,277	120,643
Software, net of amortization	71,334	68,513
Client contracts, net of amortization	82,743	184,763
Long-term debt, net of unamortized original issue discount	$ 24,003	$ 25,302
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	33,960	33,734
Treasury stock, shares	31,858	31,530