Share-Based Compensation (Schedule Of Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Options outstanding, January 1	516,674			509,422
Options outstanding, December 31	871,671		211,675	509,422
Options exercisable, December 31	644,990
Weighted Average Exercise Price, Options outstanding, January 1	$ 59.20			$ 42.03
Weighted Average Exercise Price, Options outstanding, December 31	$ 60.43		$ 46.60	$ 42.03
Weighted Average Exercise Price, Options exercisable, December 31	$ 59.79
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	3 years 4 months 28 days
Weighted Average Remaining Contractual Life (Years), Options exercisable, December 31	3 years 2 months 29 days
Aggregate Intrinsic Value, Options outstanding, December 31	$ 8,308
Aggregate Intrinsic Value, Options exercisable, December 31	$ 6,559
2005 Plan [Member]
Options granted		360,000	340,000
Options exercised	(26,670)	(55,001)	(618,481)
Weighted Average Exercise Price, Options granted		$ 64.49	$ 47.52
Weighted Average Exercise Price, Options exercised	$ 47.52	$ 45.31	$ 43.63
2012 Plan [Member]
Options granted	400,000
Options exercised	(3,333)
Options forfeited	(15,000)
Weighted Average Exercise Price, Options granted	$ 61.31
Weighted Average Exercise Price, Options exercised	$ 61.31
Weighted Average Exercise Price, Options forfeited	$ 64.49
1997 Plan [Member]
Options exercised			(19,266)
Weighted Average Exercise Price, Options exercised			$ 33.26
Grant Date 2-22-2011 [Member]
Options outstanding, December 31	15,000
Weighted Average Exercise Price, Options outstanding, December 31	$ 45.58
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	1 year 1 month 23 days
Grant Date 2-25-2011 [Member]
Options outstanding, December 31	33,336
Weighted Average Exercise Price, Options outstanding, December 31	$ 46.22
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	1 year 1 month 26 days
Grant Date 2-21-2012 [Member]
Options outstanding, December 31	81,668
Weighted Average Exercise Price, Options outstanding, December 31	$ 47.52
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	2 years 1 month 23 days
Grant Date 2-25-2013 [Member]
Options outstanding, December 31	345,000
Weighted Average Exercise Price, Options outstanding, December 31	$ 64.49
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	3 years 1 month 27 days
Grant Date 2-25-2014 [Member]
Options outstanding, December 31	396,667
Weighted Average Exercise Price, Options outstanding, December 31	$ 61.31
Weighted Average Remaining Contractual Life (Years), Options outstanding, December 31	4 years 1 month 27 days