Income Taxes (Tables)

12 Months Ended

Dec. 31, 2015

Income Tax Disclosure [Abstract]

Components of Income Before Income Taxes

For financial reporting purposes, income before income taxes includes the following components (in thousands):

	Years Ended December 31,
	2015		2014		2013
United States	$	52,563	$	47,963	$	47,640
Foreign		60,810		50,806		45,519
Total	$	113,373	$	98,769	$	93,159

Income Tax Expense (Benefit)

The expense (benefit) for income taxes consists of the following (in thousands):     

	Years Ended December 31,
	2015			2014			2013
Federal
Current	$	(6,889	)	$	7,895		$	7,509
Deferred		18,024			7,021			9,491
Total		11,135			14,916			17,000
State
Current		379			1,542			2,492
Deferred		(4,096	)		(2,397	)		(1,687	)
Total		(3,717	)		(855	)		805
Foreign
Current		15,117			13,335			9,717
Deferred		5,402			3,813			1,769
Total		20,519			17,148			11,486
Total	$	27,937		$	31,209		$	29,291

Summary of Differences Between Income Tax Expense Computed at Statutory Federal Income Tax Rate and Per Consolidated Statements of Income

Differences between the income tax expense computed at the statutory federal income tax rate and per the consolidated statements of income are summarized as follows (in thousands):

	Years Ended December 31,
	2015			2014			2013
Tax expense at federal rate of 35%	$	39,680		$	34,569		$	32,606
State income taxes, net of federal benefit		(2,462	)		(544	)		675
Change in valuation allowance		(9,066	)		3,521			(1,615	)
Foreign tax rate differential		(5,710	)		(5,508	)		(4,650	)
Unrecognized tax benefit increase		2,977			65			488
Tax effect of foreign operations		261			(104	)		5,906
Acquisition Costs		—			289			896
Tax benefit of research & development		(871	)		(3,446	)		(4,001	)
Other		3,128			2,367			(1,014	)
Income tax provision	$	27,937		$	31,209		$	29,291

Deferred Tax Assets and Liabilities Result from Differences in Timing of Recognition of Certain Income and Expense Items for Tax and Financial Accounting Purposes

The deferred tax assets and liabilities result from differences in the timing of the recognition of certain income and expense items for tax and financial accounting purposes. The sources of these differences at each balance sheet date are as follows (in thousands):

	December 31,
	2015			2014
Deferred income tax assets:
Net operating loss carryforwards	$	112,193		$	150,004
Tax credits		40,614			43,804
Compensation		25,752			24,486
Deferred revenue		25,287			13,486
Tax basis in investments		100			5,601
Other		8,246			9,712
Gross deferred income tax assets		212,192			247,093
Less: valuation allowance		(18,742	)		(36,174	)
Net deferred income tax assets	$	193,450		$	210,919
Deferred income tax liabilities:
Depreciation and amortization	$	(130,645	)	$	(129,825	)
Total deferred income tax liabilities		(130,645	)		(129,825	)
Net deferred income taxes	$	62,805		$	81,094
Deferred income taxes / liabilities included in the balance sheet are:
Deferred income tax asset - noncurrent	$	90,872		$	94,536
Deferred income tax liability - noncurrent		(28,067	)		(13,442	)
Net deferred income taxes	$	62,805		$	81,094

Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31 is as follows (in thousands):

	2015			2014			2013
Balance of unrecognized tax benefits at beginning of year	$	14,780		$	14,996		$	13,079
Increases for tax positions of prior years		1,449			84			1,560
Decreases for tax positions of prior years		(47	)		(412	)		(327	)
Increases for tax positions established for the current period		9,866			491			1,739
Decreases for settlements with taxing authorities		(594	)		—			(61	)
Reductions resulting from lapse of applicable statute of limitation		(4,218	)		(239	)		(901	)
Adjustment resulting from foreign currency translation		(157	)		(140	)		(93	)
Balance of unrecognized tax benefits at end of year	$	21,079		$	14,780		$	14,996