Supplemental Cash Flow Information (Summary Of Supplemental Cash Flow Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash Paid During The Period For
Interest	$ 3,547	$ 6,204
Income taxes, net of refunds	69	1,778
Noncash Investing and Financing Activities
Increase (decrease) in accounts payable associated with acquisition of property and equipment	(675)	(392)
Capital lease obligations	0	120
Effect Of Acquisitions And Related Transactions [Abstract]
Assets acquired, net of cash and adjustments	0	12,911
Liabilities assumed and noncontrolling interests	$ 0	$ (4,768)