Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenue	$ 594,893	$ 470,420
Cost of services and products	471,590	371,619
Gross Margin	123,303	98,801
Selling, general and administrative expense	47,316	37,734
Income from Operations	75,987	61,067
Interest income	344	167
Interest expense	(545)	(147)
Equity earnings of unconsolidated affiliates	804	470
Other income (expense), net	(1,473)	(141)
Income before Income Taxes	75,117	61,416
Provision for income taxes	23,662	19,346
Net Income	$ 51,455	$ 42,070
Cash Dividends declared per Share	$ 0.15	$ 0.00
Basic Earnings per Share	$ 0.48	$ 0.39
Diluted Earnings per Share	$ 0.47	$ 0.39