CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Revenues	$ 1,210,941	$ 1,171,614
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization)	855,901	780,836
Selling, general and administrative expenses	211,887	237,277
Depreciation and amortization expense	22,782	24,259
Income from operations	120,371	129,242
Interest and other income/(loss), net	11,521	(165)
Foreign exchange loss	(4,608)	(22,785)
Income before provision for income taxes	127,284	106,292
Provision for income taxes	24,992	16,573
Net income	$ 102,292	$ 89,719
Net income per share:
Basic (in usd per share)	$ 1.77	$ 1.58
Diluted (in usd per share)	$ 1.73	$ 1.52
Shares used in calculation of net income per share:
Basic (in shares)	57,702	56,915
Diluted (in shares)	59,298	58,941