CONDENSED CONSOLIDATED BALANCE SHEETS - UNAUDITED (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Trade accounts receivable-billed, allowance	$ 4,057	$ 3,735
Property and equipment, accumulated depreciation	100,883	98,029
Intangibles, accumulated amortization	228,326	219,204
Client contract costs, accumulated amortization	37,827	31,526
Long-term debt, unamortized discounts	$ 7,726	$ 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	33,080,000	32,891,000
Treasury stock, shares	35,507,000	35,356,000
Software
Intangibles, accumulated amortization	$ 131,835	$ 125,437
Acquired client contracts
Intangibles, accumulated amortization	$ 96,491	$ 93,767