Income Taxes (Summary Of The Provision For Income Taxes And The U.S. Federal Tax Rate) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Taxes [Abstract]
Computed "expected" tax expense, amount	$ 73,807	$ 52,948	$ 43,565
Computed "expected" tax expense, rate	35.00%	35.00%	35.00%
Foreign income tax differential, amount	(8,333)	(7,074)	(6,025)
Foreign income tax differential, rate	(3.95%)	(4.68%)	(4.65%)
State taxes net of federal benefits, amount	1,923	1,279	1,490
State taxes net of federal benefits, rate	0.91%	0.85%	1.15%
Foreign-sourced non-taxable income, amount	(4,423)	(3,873)	(2,825)
Foreign-sourced non-taxable income, rate	(2.10%)	(2.56%)	(2.18%)
Other, amount	568	104	2,558
Other, rate	0.27%	0.07%	1.98%
Total provision	$ 63,542	$ 43,384	$ 40,563
Provision for income taxes, rate	30.13%	28.68%	31.30%