Income Taxes (Tables)

12 Months Ended

Dec. 31, 2017

Income Tax Disclosure [Abstract]

Components Of Income Before Income Taxes

Income before income taxes includes the following components:

	Year Ended December 31,
(in thousands)	2017		2016		2015
Domestic	$	344,447	$	340,251	$	325,097
Foreign	51,247		40,064		31,668
Total	$	395,694	$	380,315	$	356,765

Components Of Provision For Income Taxes

The provision for income taxes is composed of the following:

	Year Ended December 31,
(in thousands)	2017			2016			2015
Current:
Federal	$	112,414		$	99,783		$	93,853
State	7,879			8,338			7,733
Foreign	18,843			17,479			17,854
Deferred:
Federal	(7,387		)	(13,368		)	(14,472		)
State	(584		)	(1,036		)	(1,987		)
Foreign	5,278			3,483			1,263
Total	$	136,443		$	114,679		$	104,244

Reconciliation Of U.S. Federal Statutory Tax Rate To Consolidated Effective Tax Rate

The reconciliation of the U.S. federal statutory tax rate to the consolidated effective tax rate is as follows:

	Year Ended December 31,
	2017		2016		2015
Federal statutory tax rate	35.0	%	35.0	%	35.0	%
U.S. tax reform	4.5		—		—
State income taxes, net of federal benefit	1.1		1.6		1.1
Uncertain tax positions	0.3		(0.2	)	(0.4	)
Benefit from restructuring activities	—		(2.2	)	(2.7	)
Research and development credits	(1.4	)	(1.0	)	(1.1	)
Domestic production activity benefit	(2.6	)	(3.7	)	(3.1	)
Stock-based compensation	(3.1	)	0.2		—
Other	0.7		0.5		0.4
	34.5	%	30.2	%	29.2	%

Components Of Deferred Tax Assets And Liabilities

The components of deferred tax assets and liabilities are as follows:

	December 31,
(in thousands)	2017			2016
Deferred tax assets:
Net operating loss carryforwards	$	21,391		$	32,969
Stock-based compensation	17,825			23,652
Uncertain tax positions	15,424			11,562
Employee benefits	8,603			17,187
Deferred revenue	5,134			6,382
Research and development credits	3,699			3,889
Allowance for doubtful accounts	1,462			2,078
Other	2,003			3,114
Valuation allowance	(1,906		)	(1,625		)
	73,635			99,208
Deferred tax liabilities:
Other intangible assets	(29,924		)	(56,195		)
Property and equipment	(1,557		)	(2,994		)
Unremitted foreign earnings	(1,504		)	49
	(32,985		)	(59,140		)
Net deferred tax assets	$	40,650		$	40,068

Reconciliation Of Unrecognized Tax Benefits

The following is a reconciliation of the total amounts of unrecognized tax benefits:

	Year Ended December 31,
(in thousands)	2017			2016			2015
Unrecognized tax benefit as of January 1	$	15,209		$	16,067		$	16,342
Gross increases—tax positions in prior period	905			983			64
Gross decreases—tax positions in prior period	(765		)	(2,502		)	(850		)
Gross increases—tax positions in current period	3,757			2,725			4,064
Reductions due to a lapse of the applicable statute of limitations	(847		)	(927		)	(2,808		)
Changes due to currency fluctuation	1,414			(348		)	(653		)
Settlements	(16		)	(789		)	(92		)
Unrecognized tax benefit as of December 31	$	19,657		$	15,209		$	16,067