Equity Investments (Schedule Of Summarized Aggregated Financial Information Related To The Subsidiaries) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Equity Investments [Abstract]
Revenues	$ 9,025	$ 23,018
Operating income	3,296	17,379
Net income	3,296	17,379
Current assets	16,776		16,682
Total assets	531,749		537,251
Current liabilities	635		706
Total liabilities	$ 5,322		$ 5,320