Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Assets, Current [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 85,135	$ 84,991
Accounts Receivable, after Allowance for Credit Loss, Current	440,190	452,573
Prepaid Expense and Other Assets, Current	109,611	92,947
Income Taxes Receivable, Current	20,301	21,785
Total current assets	655,237	652,296
Long-term assets
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization	123,274	132,051
Operating lease assets	84,944	91,263
Goodwill	571,919	571,197
Deferred tax assets, net	8,757	8,498
Other intangible assets, net	157,098	164,808
Income Taxes Receivable, Noncurrent	24,279	31,781
Other long-term assets	100,728	101,486
Total long-term assets	1,070,999	1,101,084
Total assets	1,726,236	1,753,380
Liabilities, Current [Abstract]
Accounts payable	77,406	84,180
Employee-related Liabilities, Current	116,779	137,636
Other accrued expenses	25,647	22,578
Accrued Income Taxes, Current	8,521	3,007
Deferred revenue	70,675	64,752
Current operating lease liabilities	32,116	33,358
Other Liabilities, Current	3,159	8,425
Total current liabilities	334,303	353,936
Liabilities, Noncurrent [Abstract]
Long-Term Line of Credit, Noncurrent	964,000	975,000
Deferred tax liabilities, net	19,629	17,457
Non-current operating lease liabilities	65,236	71,008
Other long-term liabilities	61,562	67,860
Total long-term liabilities	1,110,427	1,131,325
Total liabilities	1,444,730	1,485,261
Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Preferred Stock, Value, Issued	0	0
Common Stock, Value, Outstanding	478	477
Additional Paid in Capital	423,368	420,181
Treasury stock at cost: 34,328,112 and 34,328,112 shares as of March 31, 2025 and December 31, 2024, respectively	(584,900)	(584,900)
Accumulated other comprehensive income (loss)	(122,973)	(132,121)
Retained Earnings (Accumulated Deficit)	548,001	546,617
Noncontrolling interest	17,532	17,865
Total stockholders' equity	281,506	268,119
Total liabilities and stockholders' equity and mezzanine equity	$ 1,726,236	$ 1,753,380