Fair-Value Measurements (Summary Of Valuation Of Financial Instruments At Fair-Value) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis [Line Items]
Cash equivalents	$ 441,199	$ 378,266
Current marketable securities		3,200
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis [Line Items]
Cash equivalents	99,092	70,488
Current marketable securities		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis [Line Items]
Cash equivalents	342,107	307,778
Current marketable securities		3,200
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis [Line Items]
Cash equivalents	0	0
Current marketable securities		$ 0