CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Trade accounts receivable-billed, allowance	$ 3,730	$ 3,735
Property and equipment, accumulated depreciation	100,661	98,029
Intangibles, accumulated amortization	236,508	219,204
Client contract costs, accumulated amortization	39,206	31,526
Long-term debt, unamortized discounts	$ 6,543	$ 10,053
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	33,125,000	32,891,000
Treasury stock, shares	35,646,000	35,356,000
Software
Intangibles, accumulated amortization	$ 135,644	$ 125,437
Acquired client contracts
Intangibles, accumulated amortization	$ 100,864	$ 93,767