Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 174,742	$ 132,914
Accounts receivable, net of allowance of $5,940 and $5,067, respectively	354,662	378,397
Prepaids and other current assets	131,566	104,597
Income and other tax receivables	46,091	40,894
Total current assets	707,061	656,802
Long-term assets
Property, plant and equipment, net	168,685	178,706
Operating lease assets	106,735	120,820
Goodwill	733,940	363,502
Deferred tax assets, net	19,606	15,081
Other intangible assets, net	227,553	112,059
Other long-term assets	74,048	69,438
Total long-term assets	1,330,567	859,606
Total assets	2,037,628	1,516,408
Current liabilities
Accounts payable	66,858	66,658
Accrued employee compensation and benefits	156,585	163,658
Other accrued expenses	44,319	55,915
Income taxes payable	11,781	19,709
Deferred revenue	82,754	39,956
Current operating lease liabilities	42,891	43,651
Other current liabilities	5,022	6,623
Total current liabilities	410,210	396,170
Long-term liabilities
Line of credit	834,000	385,000
Deferred tax liabilities, net	6,064	7,747
Non-current Income Taxes Payable	20,706	22,291
Non-current operating lease liabilities	83,146	98,277
Other long-term liabilities	96,401	96,185
Total long-term liabilities	1,040,317	609,500
Total liabilities	1,450,527	1,005,670
Redeemable noncontrolling interest	54,800	52,976
Stockholders' equity
Preferred stock - $0.01 par value: 10,000,000 shares authorized; zero shares outstanding as of March 31, 2021 and December 31, 2020
Common stock - $0.01 par value; 150,000,000 shares authorized; 46,893,465 and 46,737,033 shares outstanding as of June 30, 2021 and December 31, 2020, respectively	469	467
Additional paid-in capital	358,423	360,293
Treasury stock at cost: 35,158,788 and 35,315,220 shares as of June 30, 2021 and December 31, 2020, respectively	(598,627)	(601,214)
Accumulated other comprehensive income (loss)	(78,328)	(72,156)
Retained earnings	834,967	757,312
Noncontrolling interest	15,397	13,060
Total stockholders' equity	532,301	457,762
Total liabilities and stockholders' equity	$ 2,037,628	$ 1,516,408