Operating expenses (Tables)

9 Months Ended

Sep. 30, 2020

Operating expenses

Schedule of Direct Operating Expenses

	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Ancillary and logistical service expenses	$	16,550	$	13,285	$	45,368	$	43,516
Employee compensation expenses		11,442		11,555		35,057		37,268
Buildings, facilities and technology expenses		1,653		1,655		7,768		5,961
Travel, advertising and promotion expenses		4,782		5,765		17,518		24,440
Other costs of services		4,796		4,122		12,315		11,534
	$	39,223	$	36,382	$	118,026	$	122,719

Schedule of Selling, General and Administrative Expenses

	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Employee compensation expenses	$	78,430	$	60,680	$	211,732	$	186,033
Buildings, facilities and technology expenses		15,901		14,569		46,108		45,066
Travel, advertising and promotion expenses		5,479		10,033		20,565		28,400
Professional fees		4,546		3,685		13,570		11,915
Other SG&A expenses		5,830		4,724		17,228		15,175
	$	110,186	$	93,691	$	309,203	$	286,589

Schedule of Depreciation and Amortization Expenses

	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Depreciation expense	$	7,705	$	7,305	$	23,278	$	21,630
Amortization expense		10,731		10,387		32,308		30,289
	$	18,436	$	17,692	$	55,586	$	51,919