Supplemental Cash Flow Information (Supplemental Cash Flow Information and Non-Cash Investing and Financing Activities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Supplemental Cash Flow Information
Cash paid during the period for interest	$ 366,458	$ 274,234	$ 219,408
Cash paid during the period for income taxes (net of refunds of $20,847, $9,277 and $9,977)	69,277	53,909	36,381
(Decrease) increase in accounts payable and accrued expenses for purchases of property and equipment and construction activities	(10,244)	8,507	11,253
Purchases of property, plant and equipment under capital leases	19,219	6,800	2,200
Fair value of debt assumed through acquisitions	$ 0	$ 209,321	$ 0