Financial Instruments (Carrying Value, Fair Value And Hierarchy Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual fund investments of deferred compensation plans held in trust, Carrying Value	$ 35,055	$ 31,629
Long-term debt, Carrying Value	168,759	166,784
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual fund investments of deferred compensation plans held in trust	35,055
Long-term debt	191,370
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual fund investments of deferred compensation plans held in trust
Long-term debt
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mutual fund investments of deferred compensation plans held in trust
Long-term debt