Long-Term Debt And Other Long-Term Liabilities (Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified			6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2012 6.625% Senior Subordinated Notes Due 2021 [Member]	May 18, 2011 6.625% Senior Subordinated Notes Due 2021 [Member]
Debt Instrument [Line Items]
Credit agreement with average interest rates, of 2.1% and 2.7% at June 30, 2012 and December 31, 2011, respectively	$ 82,900	$ 50,000
6.625% senior subordinated notes due 2021	250,000	250,000		250,000
Long-term debt (Note 5)	$ 332,900	$ 300,000
Revolving credit facility interest rate including the effect of hedging	2.10%	2.70%
Interest percentage of senior subordinated notes			6.625%	6.625%
Debt instrument maturity date			2021