Operating expenses (Tables)

6 Months Ended

Jun. 30, 2021

Operating expenses

Schedule of Direct Operating Expenses

	Three months ended				Six months ended
	June 30,				June 30,
	2021		2020		2021		2020
Ancillary and logistical service expenses	$	14,819	$	16,060	$	27,088	$	28,818
Employee compensation expenses		12,694		11,311		25,385		23,615
Buildings, facilities and technology expenses		2,304		2,076		5,005		6,115
Travel, advertising and promotion expenses		5,299		6,161		9,817		12,736
Other costs of services		3,926		3,840		7,774		7,519
	$	39,042	$	39,448	$	75,069	$	78,803

Schedule of Selling, General and Administrative Expenses

	Three months ended				Six months ended
	June 30,				June 30,
	2021		2020		2021		2020
Wages, salaries and benefits	$	70,191	$	64,453	$	148,987	$	124,541
Share-based compensation expense		7,540		6,354		11,318		8,761
Buildings, facilities and technology expenses		17,479		14,616		34,822		30,207
Travel, advertising and promotion expenses		6,824		4,817		11,986		15,086
Professional fees		5,202		4,577		10,234		9,024
Other SG&A expenses		4,583		5,815		10,550		11,398
	$	111,819	$	100,632	$	227,897	$	199,017

Schedule of Depreciation and Amortization Expenses

	Three months ended				Six months ended
	June 30,				June 30,
	2021		2020		2021		2020
Depreciation expense	$	8,345	$	7,536	$	16,182	$	15,573
Amortization expense		13,590		10,321		26,823		21,577
	$	21,935	$	17,857	$	43,005	$	37,150