Income taxes: (Tables)

12 Months Ended

Dec. 31, 2016

Income taxes:

Schedule of components of income (loss) before income taxes

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

	Years Ended December 31,
	2016			2015			2014
Domestic	$	41,759		$	21,972		$	31,645
Foreign		(17,499	)		(9,260	)		(27,154	)
Total income before income taxes	$	24,260		$	12,712		$	4,491

Schedule of income tax expense

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

	Years Ended December 31,
	2016			2015			2014
Current:
Federal	$	135		$	(9	)	$	(126	)
State		(188	)		4			(243	)
Foreign		(202	)		(96	)		(169	)
Deferred:
Federal		(8,175	)		(5,867	)		(2,352	)
State		(1,047	)		(1,959	)		(824	)
Foreign		146			111			20
Total income tax expense	$	(9,331	)	$	(7,816	)	$	(3,694	)

Schedule of deferred tax assets (liabilities)

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

	December 31,
	2016			2015
Deferred Tax Assets:
Net operating loss carry-forwards	$	373,655		$	370,344
Tax credits		2,237			2,317
Equity-based compensation		2,279			1,474
Total gross deferred tax assets		378,171			374,135
Deferred Tax Liabilities:
Depreciation and amortization		29,984			18,038
Accrued liabilities and other		95,606			97,417
Total gross deferred tax liabilities		125,590			115,455
Net deferred tax assets before valuation allowance		252,581			258,680
Valuation allowance		(210,340	)		(213,538	)
Net deferred tax assets	$	42,241		$	45,142

Schedule of reconciliation of unrecognized tax benefits

       A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands):

	Years Ended December 31,
	2016			2015			2014
Beginning balance of unrecognized tax benefits	$	776		$	866		$	1,000
Change attributable to tax positions taken during a prior period		—			—			82
Decrease attributable to settlements with taxing authorities		(776	)		—			(160	)
Decrease attributable to lapses of statutes of limitation		—			(90	)		(56	)
Ending balance of unrecognized tax benefits	$	—		$	776		$	866

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,
	2016			2015			2014
Federal income tax (expense) benefit at statutory rates	$	(8,492	)	$	(4,450	)	$	(1,572	)
Effect of:
State income taxes, net of federal benefit		(1,080	)		(1,710	)		(590	)
Impact of foreign operations		138			(179	)		(267	)
Non-deductible expenses		(590	)		(1,253	)		(659	)
Changes in tax reserves		175			128			165
Other		98			(16	)		(191	)
Changes in valuation allowance		420			(336	)		(580	)
Income tax expense	$	(9,331	)	$	(7,816	)	$	(3,694	)