v2.3.0.15
Supplemental Cash Flow Information (Details) (USD $)
9 Months Ended
Sep. 30, 2011
Sep. 30, 2010
Cash paid for interest$ 183,728,000$ 160,741,000
Cash paid for income taxes4,113,0002,359,000
Non-cash investing and financing activities  
Accrued purchases of property and equipment136,500,00071,100,000
Assets acquired under capital lease obligations25,000,00023,600,000
Equipment returned for credit applicable for additional equipment 19,900,000
Noncash acquisition of intangible assets $ 22,000,000