Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Constituents of Provision for Income Taxes

Income tax expense on continuing operations consisted of the following (in thousands):

	Year Ended December 31,
	2018			2017			2016
Current:
Federal	$	10,624		$	78,152		$	14,459
State	(879		)	2,687			(617		)
Foreign	6,307			7,624			7,309
	16,052			88,463			21,151
Deferred:
Federal	(1,271		)	1,569			(3,031		)
State	554			(639		)	1,066
Foreign	(28		)	359			(1,058		)
	(745		)	1,289			(3,023		)
	$	15,307		$	89,752		$	18,128

Reconciliation of the United States Federal Statutory Corporate Tax Rate to the Company's Effective Tax Rate or Income Tax Provision

A reconciliation of the U.S. federal statutory corporate tax rate to the Company’s income tax expense on continuing operations, or effective tax rate, was as follows:

	Year Ended December 31,
	2018		2017		2016
Income tax expense at U.S. federal statutory corporate tax rate	21	%	35	%	35	%
State income taxes, net of federal benefit	1		—		1
Foreign tax rate differential	(9	)	(27	)	(17	)
Tax credit	—		(1	)	(1	)
Discrete tax benefit related to employee stock option exercises	(4	)	(14	)	(7	)
Discrete tax expense (benefit) related to 2017 Tax Act	(3	)	36		—
Discrete tax expense related to write-down of deferred tax assets	—		5		—
Other discrete tax events	—		(1	)	—
Other	1		1		—
Income tax expense on continuing operations	7	%	34	%	11	%

Changes in the Reserve for Income Taxes, Excluding Interest and Penalties

The changes in the reserve for income taxes, excluding gross interest and penalties, were as follows (in thousands):

Balance of reserve for income taxes as of December 31, 2016	$	5,719
Gross amounts of decreases in unrecognized tax benefits as a result of tax positions taken in prior periods	(56		)
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in the current period	1,993
Gross amounts of decreases in unrecognized tax benefits relating to settlements with taxing authorities	(116		)
Gross amounts of decreases in unrecognized tax benefits as a result of the expiration of the applicable statutes of limitations	(791		)
Balance of reserve for income taxes as of December 31, 2017	6,749
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in prior periods	69
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in the current period	1,499
Gross amounts of decreases in unrecognized tax benefits as a result of the expiration of the applicable statutes of limitations	(1,023		)
Balance of reserve for income taxes as of December 31, 2018	$	7,294

Constituents of Deferred Tax Assets

Deferred tax assets and liabilities consisted of the following (in thousands):

	December 31,
	2018			2017
Non-current deferred tax assets:
Stock-based compensation expense	$	13,818		$	11,664
Federal and state tax credit carryforwards	7,395			6,707
Bonuses, commissions, and other compensation	5,470			5,704
Inventory and revenue related	3,233			3,415
Depreciation	2,475			2,279
Other	2,425			3,012
Gross non-current deferred tax assets	34,816			32,781
Non-current deferred tax liabilities:
Nondeductible intangible assets	(44		)	(87		)
Gross non-current deferred tax liabilities	(44		)	(87		)
Valuation allowance	(6,112		)	(5,309		)
Net non-current deferred tax assets	$	28,660		$	27,385
Non-current deferred tax liabilities:
Other	$	(962	)	$	(312	)
Net non-current deferred tax liabilities	$	(962	)	$	(312	)