v2.3.0.11
Supplemental Cash Flow Information (Details) (USD $)
6 Months Ended
Jun. 30, 2011
Jun. 30, 2010
Cash paid for interest $ 113,313,000 $ 134,690,000
Cash paid for income taxes 3,873,000 2,237,000
Non-cash investing and financing activities    
Accrued purchases of property and equipment 96,900,000 81,800,000
Assets acquired under capital lease obligations 20,300,000 10,400,000
Equipment returned for credit applicable for additional equipment   $ 17,800,000