LONG-TERM DEBT AND FINANCING ARRANGEMENTS (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Assets held under capital leases or securitized by notes payable
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	$ 1,079,320	$ 1,007,589
Less accumulated amortization	635,292	592,171
TOTAL PROPERTY, PLANT AND EQUIPMENT, NET	444,028	415,418
Assets held under capital leases or securitized by notes payable
Assets held under capital leases or securitized by notes payable
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	96,611	95,532
Less accumulated amortization	35,183	26,759
TOTAL PROPERTY, PLANT AND EQUIPMENT, NET	61,428	68,773
Land and structures (terminals) | Assets held under capital leases or securitized by notes payable
Assets held under capital leases or securitized by notes payable
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	1,794	1,794
Revenue equipment | Assets held under capital leases or securitized by notes payable
Assets held under capital leases or securitized by notes payable
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	93,004	91,925
Service, office, and other equipment | Assets held under capital leases or securitized by notes payable
Assets held under capital leases or securitized by notes payable
TOTAL PROPERTY, PLANT AND EQUIPMENT, GROSS	$ 1,813	$ 1,813