Operating Expenses

12 Months Ended

Dec. 31, 2018

Operating Expenses [Abstract]

Operating Expenses

6.  Operating expenses

Costs of services

Year ended December 31,		2018		2017		2016
Ancillary and logistical service expenses	$	66,576	$	54,176	$	47,234
Employee compensation expenses		41,391		35,440		27,856
Buildings, facilities and technology expenses		9,477		8,359		7,966
Travel, advertising and promotion expenses		27,606		23,994		23,688
Other costs of services		14,008		11,220		6,552
	$	159,058	$	133,189	$	113,296

SG&A expenses

Year ended December 31,		2018		2017		2016
Employee compensation expenses	$	249,115	$	208,370	$	180,929
Buildings, facilities and technology expenses		60,930		53,151		49,219
Travel, advertising and promotion expenses		36,728		30,440		24,384
Professional fees		16,768		13,522		13,344
Other SG&A expenses		19,135		17,787		15,653
	$	382,676	$	323,270	$	283,529

Acquisition-related costs

Acquisition-related costs consist of operating expenses directly incurred as part of a business combination, due diligence and integration planning related to the IronPlanet acquisition (note 29), and continuing employment costs that are recognized separately from our business combinations.

Year ended December 31,		2018		2017		2016
IronPlanet:
Other acquisition-related costs	$	2,944	$	34,653	$	8,202
Other acquisitions:
Continuing employment costs		2,091		3,418		2,491
Other acquisition-related costs		58		201		1,136
	$	5,093	$	38,272	$	11,829

Depreciation and amortization expenses

Year ended December 31,		2018		2017		2016
Depreciation expense	$	29,021	$	28,337	$	30,983
Amortization expense		37,593		24,357		9,878
	$	66,614	$	52,694	$	40,861

During the year ended December 31, 2018, depreciation expense of $494,000 (2017:  $1,207,000; 2016: $2,880,000) and amortization expense of $18,996,000 (2017:  $11,662,000; 2016: $7,218,000) were recorded relating to software.