Long-Term Debt (Schedule Of Long-Term Debt) (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended	3 Months Ended
	May 10, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Debt Instrument [Line Items]
Total debt		$ 630,256	$ 739,989	$ 450,383
Less current portion		(22,606)	(22,606)	(22,606)
Total long-term debt		607,650	717,383	427,777
Domestic And Multi Currency Line Of Credit Due Twenty Eighteen [Member]
Debt Instrument [Line Items]
Total debt		148,620	193,717	179,321
Debt instrument, maturity year		2018
6.09% Series A Senior Unsecured Notes Due 2016 [Member]
Debt Instrument [Line Items]
Total debt		21,000	21,000	28,000
Debt instrument, maturity year		2016
Debt instrument, interest rate		6.09%
7.26% Senior Unsecured Notes Due 2017 [Member]
Debt Instrument [Line Items]
Total debt		15,000	20,000	20,000
Debt instrument, maturity year		2017
Debt instrument, interest rate		7.26%
Variable Rate Senior Unsecured Note Due 2018 [Member]
Debt Instrument [Line Items]
Total debt		31,250	33,333	39,583
Debt instrument, maturity year	2018	2018
5.75% senior unsecured notes due 2018
Debt Instrument [Line Items]
Total debt		300,000	300,000	0
Debt instrument, maturity year		2018
Debt instrument, interest rate		5.75%
6.00% Series A Senior Unsecured Notes Due 2019 [Member]
Debt Instrument [Line Items]
Total debt		47,000	47,000	47,000
Debt instrument, maturity year		2019
Debt instrument, interest rate		6.00%
6.21%Series B Senior Unsecured Notes Due 2021 [Member]
Debt Instrument [Line Items]
Total debt		18,182	18,182	20,455
Debt instrument, maturity year		2021
Debt instrument, interest rate		6.21%
6.58% Series B Senior Unsecured Notes Due 2022 [Member]
Debt Instrument [Line Items]
Total debt		5,000	5,000	5,000
Debt instrument, maturity year		2022
Debt instrument, interest rate		6.58%
5.25% Convertible Senior Unsecured Notes Due 2029 [Member]
Debt Instrument [Line Items]
Total debt		$ 44,204	$ 101,757	$ 111,024
Debt instrument, maturity year		2029
Debt instrument, interest rate		5.25%