Consolidated Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenue	$ 718,552	$ 594,893
Cost of services and products	558,177	471,590
Gross Margin	160,375	123,303
Selling, general and administrative expense	52,085	47,316
Income from Operations	108,290	75,987
Interest income	190	344
Interest expense	(763)	(545)
Equity earnings of unconsolidated affiliates	161	804
Other income (expense), net	1,390	(1,473)
Income before Income Taxes	109,268	75,117
Provision for income taxes	34,419	23,662
Net Income	$ 74,849	$ 51,455
Cash Dividends declared per Share	$ 0.18	$ 0.15
Basic Earnings per Share	$ 0.69	$ 0.48
Diluted Earnings per Share	$ 0.69	$ 0.47