Goodwill and Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance	$ 188,169	$ 186,805	$ 186,925
Write-offs			(136)
Impact of foreign currency translation	(2,074)	1,364	16
Ending balance	186,095	188,169	186,805
Warehouse
Goodwill [Roll Forward]
Beginning balance	172,554	171,582	171,498
Write-offs			(112)
Impact of foreign currency translation	(1,658)	972	196
Ending balance	170,896	172,554	171,582
Third-party managed
Goodwill [Roll Forward]
Beginning balance	3,064	3,056	3,179
Write-offs			0
Impact of foreign currency translation	(174)	8	(123)
Ending balance	2,890	3,064	3,056
Transportation
Goodwill [Roll Forward]
Beginning balance	12,551	12,167	12,248
Write-offs			(24)
Impact of foreign currency translation	(242)	384	(57)
Ending balance	$ 12,309	$ 12,551	$ 12,167