Statement Of Cash Flow Information (Narrative) (Details) (USD $)	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Statement Of Cash Flow Information [Abstract]
Restricted cash and cash equivalents, noncurrent	$ 31,081,000		$ 33,741,000
Accruals for capital expenditures	$ 37,800,000	$ 33,700,000