Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Rollforward of goodwill by reportable segment

The following is a rollforward of goodwill from December 31, 2015 to December 31, 2017 by segment (in thousands): 

	TL			LTL			Ascent			Total
Goodwill balance as of December 31, 2015	$	254,940		$	197,312		$	230,558		$	682,810
Adjustments to goodwill for purchase accounting	1,812			—			—			1,812
Goodwill impairment charges	(157,538		)	(197,312		)	(17,231		)	(372,081		)
Goodwill balance as of December 31, 2016	$	99,214		$	—		$	213,327		$	312,541
Adjustments to goodwill for purchase accounting	(470		)	—			—			(470		)
Adjustments to goodwill for sale of Unitrans	—			—			(42,843		)	(42,843		)
Goodwill impairment charges	—			—			(4,402		)	(4,402		)
Goodwill balance as of December 31, 2017	$	98,744		$	—		$	166,082		$	264,826

Intangible assets

Intangible assets consist primarily of customer relationships acquired from business acquisitions. Intangible assets were as follows as of December 31 (in thousands):

	2017							2016
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Value		Gross Carrying Amount		Accumulated Amortization			Net Carrying Value
TL	$	55,733	$	(18,907	)	$	36,826	$	54,973	$	(13,606	)	$	41,367
LTL	2,498		(1,748		)	750		1,358		(1,083		)	275
Ascent	26,427		(14,355		)	12,072		38,427		(14,520		)	23,907
Total intangible assets	$	84,658	$	(35,010	)	$	49,648	$	94,758	$	(29,209	)	$	65,549

Estimated amortization expense

Estimated amortization expense for each of the next five years based on intangible assets as of December 31, 2017 is as follows (in thousands):

	Amount
Year Ending:
2018	$	7,123
2019	6,819
2020	6,447
2021	6,265
2022	5,525
Thereafter	17,469
Total	$	49,648