INCOME TAXES (Tables)

12 Months Ended

Dec. 31, 2018

Schedule of components of income tax expense

The components of the provision for income taxes attributable to operations consist of the following (in thousands):



	Year Ended December 31,
	2018			2017			2016
Current:
Federal	$	36,167		$	41,453		$	32,198
State	5,140			3,518			3,682
Foreign	708			295			76
Total current	42,015			45,266			35,956
Deferred:
Federal	6,576			(7,917		)	12,586
State	(2,582		)	4,695			3,014
Foreign	(328		)	319			35
Total deferred	3,666			(2,903		)	15,635
Total provision for income taxes	$	45,681		$	42,363		$	51,591

Schedule of deferred tax assets and liabilities

The components of deferred tax assets and liabilities consist of the following (in thousands):



	December 31,
	2018			2017
Deferred tax assets:
Reserve for bad debts	$	1,457		$	1,636
Accrued compensation	4,803			6,706
Stock compensation	10,041			10,568
Net operating losses	26,349			25,899
Accrued reserve and other	1,773			1,578
Deferred rent	5,928			6,533
Deferred gain on the sale of building	4,140			4,741
Research and development credits	6,331			—
Total deferred tax assets, prior to valuation allowance	60,822			57,661

Valuation allowance	(14,246		)	(13,032		)
Total deferred tax assets, net of valuation allowance	46,576			44,629

Deferred tax liabilities:
Deferred commission costs, net	(19,314		)	—
Prepaid expenses	(2,204		)	(1,239		)
Property and equipment, net	(5,367		)	(6,229		)
Intangible assets, net	(82,079		)	(43,800		)
Total deferred tax liabilities	(108,964		)	(51,268		)

Net deferred tax assets (liabilities)	$	(62,388	)	$	(6,639	)

Schedule of effective income tax rate reconciliation

The Company’s provision for income taxes resulted in effective tax rates that varied from the statutory federal income tax rate as follows (in thousands):



	Year Ended December 31,
	2018			2017			2016

Expected federal income tax provision at statutory rate	$	59,643		$	57,770		$	47,832
State income taxes, net of federal benefit	10,312			4,776			3,638
Foreign income taxes, net effect	(315		)	(3,540		)	(31		)
Increase (decrease) in valuation allowance	1,214			3,624			(103		)
Tax rate changes	141			(7,340		)	283
Research credits	(15,373		)	(20,547		)	(920		)
Excess tax benefit	(14,227		)	(7,010		)	—
Tax reserves	1,870			12,646			(150		)
Other adjustments	2,416			1,984			1,042
Income tax expense	$	45,681		$	42,363		$	51,591

Schedule of unrecognized tax benefits

The following table summarizes the activity related to the Company’s unrecognized tax benefits (in thousands):



Unrecognized tax benefit as of December 31, 2015	$	7,664
Increase for current year tax positions	368
Decrease for prior year tax positions	(6,115		)
Expiration of the statute of limitation for assessment of taxes	(74		)
Unrecognized tax benefit as of December 31, 2016	1,843
Increase for current year tax positions	12,620
Decrease for prior year tax positions	(34		)
Expiration of the statute of limitation for assessment of taxes	(66		)
Unrecognized tax benefit as of December 31, 2017	14,363
Increase for current year tax positions	9,561
Decrease for prior year tax positions	(70		)
Expiration of the statute of limitation for assessment of taxes	(1,482		)
Unrecognized tax benefit as of December 31, 2018	$	22,372