Segment Reporting (Tables)

12 Months Ended

Dec. 31, 2014

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

	Years ended December 31,
(Dollars in thousands)	2014			2013		2012
Revenue from External Customers
Freight	$	3,586,333		$	3,424,002	$	3,339,605
Logistics	1,638,967			1,474,507		1,677,279
Truckload	572,990			567,255		558,714
Corporate and Eliminations	7,779			7,592		4,649
	$	5,806,069		$	5,473,356	$	5,580,247
Revenue from Internal Customers
Freight	$	45,732		$	42,098	$	52,991
Logistics	78,744			65,892		48,921
Truckload	58,521			69,555		76,842
Corporate and Eliminations	70,458			70,687		53,015
	$	253,455		$	248,232	$	231,769
Operating Income (Loss)
Freight	$	210,324		$	146,047	$	143,869
Logistics	27,193			23,467		44,616
Truckload	41,245			38,691		44,921
Corporate and Eliminations	(10,312		)	748		(4,565		)
	$	268,450		$	208,953	$	228,841
Depreciation and Amortization, net of Accretion
Freight	$	150,528		$	135,311	$	124,372
Logistics	11,225			7,571		7,532
Truckload	68,382			74,449		69,799
Corporate and Eliminations	12,372			11,905		13,499
	$	242,507		$	229,236	$	215,202
Capital Expenditures
Freight	$	176,933		$	180,576	$	190,218
Logistics	15,577			24,587		7,186
Truckload	91,731			74,637		93,117
Corporate and Eliminations	5,535			2,143		2,614
	$	289,776		$	281,943	$	293,135
Assets
Freight	$	1,560,324		$	1,529,681	$	1,459,576
Logistics	367,081			318,266		302,295
Truckload	792,088			799,775		807,470
Corporate and Eliminations	616,125			632,209		583,074
	$	3,335,618		$	3,279,931	$	3,152,415

Revenue Classified By Major Geographic Areas

	Years ended December 31,
(Dollars in thousands)	2014		2013		2012
Revenue
United States	$	5,310,573	$	5,094,193	$	5,189,792
Canada	180,951		116,491		114,451
Other	314,545		262,672		276,004
Total	$	5,806,069	$	5,473,356	$	5,580,247