Income taxes: (Tables)

12 Months Ended

Dec. 31, 2021

Income taxes:

Schedule of components of (loss) income before income taxes

The components of income before income taxes consist of the following (in thousands):

	Years Ended December 31,
	2021		2020		2019
Domestic	$	73,753	$	23,808	$	72,773
Foreign		(2,333)		(13,496)		(20,099)
Total income before income taxes	$	71,420	$	10,312	$	52,674

Schedule of income tax expense

The income tax expense is comprised of the following (in thousands):

	Years Ended December 31,
	2021		2020		2019
Current:
Federal	$	—	$	32	$	—
State		(3,116)		(2,908)		(2,647)
Foreign		(1,833)		(947)		(370)
Deferred:
Federal		(17,959)		(1,867)		(10,899)
State		(2,348)		1,241		(1,285)
Foreign		2,021		353		47
Total income tax expense	$	(23,235)	$	(4,096)	$	(15,154)

Schedule of net deferred tax assets

Our consolidated temporary differences comprising our net deferred tax assets are as follows (in thousands):

	December 31,
	2021		2020
Deferred Tax Assets:
Net operating loss carry-forwards	$	246,276	$	273,999
Tax credits		2,119		1,965
Equity-based compensation		3,976		4,901
Operating leases		40,627		40,081
Total gross deferred tax assets		292,998		320,946
Valuation allowance		(132,800)		(150,589)
		160,198		170,357
Deferred Tax Liabilities:
Depreciation and amortization		46,642		37,364
Accrued liabilities and other		103,705		105,554
Right-of-use assets		37,784		37,097
Gross deferred tax liabilities		188,131		180,015
Net deferred tax liabilities	$	27,933	$	9,658

Schedule of reconciliation of the Federal statutory income taxes to the amounts reported in the financial statements

The following is a reconciliation of the Federal statutory income taxes to the amounts reported in the financial statements (in thousands).

	Years Ended December 31,
	2021		2020		2019
Federal income tax expense at statutory rates	$	(14,999)	$	(2,166)	$	(11,061)
Effect of:
State income taxes, net of federal benefit		(4,123)		(1,091)		(2,973)
Impact of foreign operations		715		(365)		(505)
Non-deductible expenses		(1,365)		(411)		(491)
Tax effect of TCJA from foreign earnings		(389)		(66)		(28)
Other		—		32		(32)
Changes in valuation allowance		(3,074)		(29)		(64)
Income tax expense	$	(23,235)	$	(4,096)	$	(15,154)