Micrel (MCRL) 10-Q 29 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014
Document and Entity Information [Abstract]	'
Entity Registrant Name	'MICREL INC
Entity Central Index Key	'0000932111
Document Type	'10-Q
Document Period End Date	31-Mar-14
Amendment Flag	'false
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q1
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Accelerated Filer
Entity Common Stock, Shares Outstanding	56,474,252

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$26,957	$23,787
Restricted cash	1,116	1,116
Short-term investments	63,286	64,806
Accounts receivable, less allowances: 2014, $846; 2013, $760	35,934	29,437
Inventories	41,989	43,201
Prepaid taxes	878	4,513
Prepaid expenses and other	2,324	2,698
Deferred income taxes	22,321	21,662
Total current assets	194,805	191,220
LONG-TERM INVESTMENTS	4,325	4,195
PROPERTY, PLANT AND EQUIPMENT, NET	55,966	57,779
LONG-TERM PREPAID TAXES	1,725	0
GOODWILL	8,655	8,554
INTANGIBLE ASSETS, NET	10,910	11,749
DEFERRED INCOME TAXES	1,975	1,581
OTHER ASSETS	1,583	1,046
TOTAL	279,944	276,124
CURRENT LIABILITIES:	'	'
Accounts payable	14,427	13,502
Accrued liabilities	13,343	12,874
Deferred income on shipments to distributors	28,989	27,026
Total current liabilities	56,759	53,402
LONG-TERM INCOME TAXES PAYABLE	3,692	3,575
LONG-TERM DEFERRED INCOME TAXES	1,220	973
OTHER LONG-TERM LIABILITIES	201	201
Total liabilities	61,872	58,151
COMMITMENTS AND CONTINGENCIES (Note 13)	'	'
SHAREHOLDERS' EQUITY:	'	'
Preferred stock, no par value - authorized: 5,000,000 shares; issued and outstanding: none	0	0
Common stock, no par value - authorized: 250,000,000 shares; issued and outstanding: 2014 - 56,474,252 shares; 2013 - 56,441,346 shares	544	0
Accumulated other comprehensive loss	-240	-320
Retained earnings	217,768	218,293
Shareholders' Equity	218,072	217,973
TOTAL	$279,944	$276,124

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowances for accounts receivable	$846	$760
Preferred stock, par value	'	'
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	'	'
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	56,474,252	56,441,346
Common stock, shares outstanding	56,474,252	56,441,346

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Income Statement [Abstract]	'		'
NET REVENUES	$59,857		$59,733
COST OF REVENUES	28,638	[1]	28,653	[1]
GROSS PROFIT	31,219		31,080
OPERATING EXPENSES:	'		'
Research and development	15,481	[1]	13,771	[1]
Selling, general and administrative	12,436	[1]	11,861	[1]
Total operating expenses	27,917		25,632
INCOME FROM OPERATIONS	3,302		5,448
OTHER INCOME (EXPENSE):	'		'
Interest income	103		126
Other income (expense), net	-72		-91
Total other income (expense), net	31		35
INCOME BEFORE INCOME TAXES	3,333		5,483
PROVISION FOR INCOME TAXES	1,044		238
NET INCOME	$2,289		$5,245
NET INCOME PER SHARE:	'		'
Basic (Per Share)	$0.04		$0.09
Diluted (Per Share)	$0.04		$0.09
CASH DIVIDENDS DECLARED PER COMMON SHARE	$0.05		$0
WEIGHTED AVERAGE SHARES USED IN COMPUTING PER SHARE AMOUNTS:	'		'
Basic (Shares)	56,388		58,270
Diluted (Shares)	57,208		59,030
[1]	Share-based compensation expense included in:Cost of revenues$234B $244Research and development690B 652Selling, general and administrative798B 723

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Income (Parenthetical) (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Share-based compensation expense included in:	'		'
Cost of revenues	$28,638	[1]	$28,653	[1]
Research and development	15,481	[1]	13,771	[1]
Selling, general and administrative	12,436	[1]	11,861	[1]
Share-Based Compensation Expense	'		'
Share-based compensation expense included in:	'		'
Cost of revenues	234		244
Research and development	690		652
Selling, general and administrative	$798		$723
[1]	Share-based compensation expense included in:Cost of revenues$234B $244Research and development690B 652Selling, general and administrative798B 723

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
NET INCOME	$2,289	$5,245
Other comprehensive income:	'	'
Unrealized gains on investments	122	384
Reclassification adjustment for a realized loss on investment included in other expense	0	26
Income taxes	-42	-140
Other comprehensive income, net of taxes	80	270
COMPREHENSIVE INCOME	$2,369	$5,515

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:	'	'
Net income	$2,289	$5,245
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	3,469	3,404
Share-based compensation expense	1,722	1,619
Excess tax benefits from stock-based awards	-267	-89
Deferred income tax provision	-849	-833
Changes in operating assets and liabilities	'	'
Accounts receivable	-6,497	-3,757
Inventories	1,204	466
Prepaid taxes	1,641	1,244
Prepaid expenses and other assets	12	-536
Accounts payable	1,213	-3,817
Income taxes payable	117	583
Accrued liabilities and other long-term liabilities	409	1,653
Deferred income on shipments to distributors	1,963	2,544
Net cash provided by operating activities	6,426	7,726
CASH FLOWS FROM INVESTING ACTIVITIES:	'	'
Purchases of property, plant and equipment	-1,321	-1,551
Purchases of investments	-17,265	-9,037
Proceeds from sale and maturities of investments	18,778	29,500
Change in restricted cash	0	102
Net cash provided by investing activities	192	19,014
CASH FLOWS FROM FINANCING ACTIVITIES:	'	'
Proceeds from the issuance of common stock	2,351	1,508
Repurchases of common stock	-3,000	0
Payment of cash dividends	-2,814	0
Purchase of stock for withholding taxes on vested restricted stock	-252	-134
Excess tax benefits from stock-based awards	267	89
Net cash (used in) provided by financing activities	-3,448	1,463
NET INCREASE IN CASH AND CASH EQUIVALENTS	3,170	28,203
CASH AND CASH EQUIVALENTS - Beginning of period	23,787	27,281
CASH AND CASH EQUIVALENTS - End of period	$26,957	$55,484

Significant_Accounting_Policie

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
SIGNIFICANT ACCOUNTING POLICIES	'
	SIGNIFICANT ACCOUNTING POLICIES
	Interim Financial Information - The accompanying condensed consolidated financial statements of Micrel, Incorporated and its wholly-owned subsidiaries (together “Micrel” or the “Company”) as of March 31, 2014 and for the three months ended March 31, 2014 and 2013 are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) that management considers necessary for a fair statement of its financial position, operating results, comprehensive income and cash flows for the interim periods presented. Operating results and cash flows for interim periods are not necessarily indicative of results for the entire year. The Condensed Consolidated Balance Sheet as of December 31, 2013, was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted (“GAAP”) in the United States of America. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013. These financial statements should also be read in conjunction with the Company’s critical accounting policies included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 and those included in this Form 10-Q below.
	Net Income Per Share - Basic net income per share is computed by dividing net income by the number of weighted-average common shares outstanding. Diluted net income per share reflects potential dilution from outstanding stock options and restricted stock units ("RSUs") using the treasury stock method. Reconciliation of weighted-average shares used in computing basic and diluted net income per share is as follows (in thousands):
		Three Months Ended
		March 31,
		2014	2013
	Weighted average common shares outstanding	56,388	58,270
	Dilutive effect of stock options and restricted stock units	820	760
	Shares used in computing diluted net income per share	57,208	59,030
	For the three months ended March 31, 2014 and 2013, 4.7 million and 5.3 million shares underlying stock options, respectively, have been excluded from the weighted-average number of common shares outstanding for the diluted net income per share computations as they were anti-dilutive.
	Goodwill - Goodwill represents the excess of the purchase price over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is measured and tested for impairment annually at the reporting unit level during the last quarter of the Company’s fiscal year, or more frequently if the Company believes indicators of impairment exist. Events that could trigger a more frequent impairment review may include adverse industry or economic trends, restructuring actions, lower projections of profitability, or a sustained decline in our market capitalization.
	On April 2, 2012, the Company acquired PhaseLink™ Company Limited (“Phaselink”) and recorded $6.1 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets. On September 9, 2013, the Company acquired specific net assets of Discera Inc. (“Discera”) and recorded $2.5 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets. During the first quarter of 2014, goodwill recorded from the Discera transaction was increased by approximately $0.1 million to $2.6 million. The goodwill for each acquisition was allocated to the timing and communications reporting unit and is reviewed annually in October or whenever events or circumstances occur which indicate that goodwill might be impaired.

Recently_Issued_Accounting_Sta

Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
RECENTLY ISSUED ACCOUNTING STANDARDS	'
	RECENTLY ISSUED ACCOUNTING STANDARDS
	In April 2014, the Financial Accounting Standards Board issued an accounting standards update to change the requirements for reporting discontinued operations. This guidance modifies the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity's operations and financial results. The guidance requires expanded disclosures for discontinued operations for the assets, liabilities, revenues, and expenses of discontinued operations, and also requires an entity to disclose the pretax profit or loss of an individually significant component of an entity that does not qualify for discontinued operations reporting. The Company is required to adopt this standard for its interim and annual periods beginning after December 15, 2014. The Company is currently evaluating the impact of adopting this guidance.

ShareBased_Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
SHARE-BASED COMPENSATION	'
	SHARE-BASED COMPENSATION
	Share-based compensation expense is measured at the grant date based on the fair value of the award and is recognized over the employee’s requisite service period. The following table summarizes total share-based compensation expense included in the Condensed Consolidated Statement of Operations (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Cost of revenues	$	234			$	244
	Research and development	690				652
	Selling, general and administrative	798				723
	Pre-tax share-based compensation expense	1,722				1,619
	Less income tax effect	(549		)		(550		)
	Net share-based compensation expense	$	1,173			$	1,069
	During the three months ended March 31, 2014, the Company granted 0.2 million stock options at a weighted average fair value of $2.79. During the three months ended March 31, 2013, the Company granted 0.2 million stock options at a weighted average fair value of $2.91 per share. The fair value of the Company’s stock options granted under the Company’s option plans was estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions:
		Three Months Ended
		March 31,
		2014			2013
	Expected term (years)	6.1			5.9
	Stock volatility	31	%		33.5	%
	Risk free interest rates	2.1	%		1	%
	Dividends during expected terms	1.8	%		1.6	%
	The Company also grants RSUs to its employees. In the three months ended March 31, 2014 and 2013, the Company granted 0.2 million and 0.1 million RSUs, respectively, at weighted average fair values of $9.81 and $10.07, respectively.
	As of March 31, 2014, there was $6.5 million of total unrecognized share-based compensation related to non-vested stock option awards and $9.0 million related to non-vested RSUs, which are expected to be recognized over a weighted-average period of 2.8 and 3.1 years, respectively. Total share-based compensation expense capitalized as part of inventory as of March 31, 2014 and December 31, 2013 was $0.1 million and $0.2 million, respectively.
	Under the Company’s Employee Stock Purchase Plan (“ESPP”), eligible employees are permitted to have salary withholdings to purchase shares of Common Stock at a price equal to 95% of the market value of the stock at the end of each three-month offer period, subject to an annual limitation. The ESPP is considered non-compensatory per current share-based compensation accounting guidelines.

Investments

Investments	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
INVESTMENTS	'
	INVESTMENTS
	Investments purchased with remaining maturity dates of less than three months are classified as cash equivalents. Investments are classified either as short-term or as long-term based on maturities and the Company’s intent with regard to those securities (expectations of sales and redemptions). Short-term investments as of March 31, 2014 consisted primarily of liquid municipal and corporate debt instruments with maturities ranging from less than one month to less than two years and were classified as available-for-sale securities. Long-term investments as of March 31, 2014 consisted of auction-rate notes secured by student loans and were classified as available-for-sale securities. Available-for-sale securities are stated at market value with unrealized gains and losses included in accumulated other comprehensive loss, a component of shareholders' equity. Unrealized losses are charged against income when a decline in the fair market value of an individual security is determined to be other than temporary. Realized gains and losses on investments are included in other income or expense.
	A summary of the Company’s short-term investments at March 31, 2014 and December 31, 2013 was as follows (in thousands):
		As of March 31, 2014									As of December 31, 2013
		Cost		Gross Unrealized		Gross Unrealized			Fair		Cost		Gross Unrealized		Gross Unrealized Losses			Fair
				Gains		Losses			Value				Gains					Value
	Municipal Securities	$	15,163	$	2	$	—		$	15,165	$	13,858	$	—	$	(2	)	$	13,856
	Corporate Debt Securities	37,145		—		(1		)	37,144		36,947		10		—			36,957
	Commercial Paper	10,976		1		—			10,977		13,991		2		—			13,993
	Total	$	63,284	$	3	$	(1	)	$	63,286	$	64,796	$	12	$	(2	)	$	64,806
	As of March 31, 2014, the Company had no short-term investments that have been in a significant continuous unrealized loss position for more than twelve months.
	A summary of the Company’s long-term investments at March 31, 2014 and December 31, 2013 was as follows (in thousands):
		As of March 31, 2014									As of December 31, 2013
		Cost		Gross Unrealized		Gross Unrealized			Fair		Cost		Gross Unrealized		Gross Unrealized			Fair
				Gains		Losses			Value				Gains		Losses			Value
	Auction Rate Notes	$	4,700	$	—	$	(375	)	$	4,325	$	4,700	$	—	$	(505	)	$	4,195
	As of March 31, 2014, the Company had $4.7 million of auction-rate notes. Auction-rate notes are securities that are structured with short-term interest rate reset dates of generally less than ninety days, but with contractual maturities that can be in excess of ten years. At the end of each reset period, which occurs every seven or twenty-eight days for the securities held by the Company, investors can sell or continue to hold the securities at par. As a result of sell orders exceeding buy orders, auctions for the student loan-backed notes held by the Company have failed as of March 31, 2014. To date the Company has collected all interest receivable on all of its auction-rate notes when due and expects to continue to do so in the future. The principal associated with failed auctions will not be accessible until a successful auction occurs, a buyer is found outside of the auction process, the issuers redeem the securities, the issuers repay principal over time from cash flows prior to final maturity or final payments come due according to contractual maturities ranging from 18 to 34 years. As a result, the Company has classified all auction-rate notes as long-term investments as of March 31, 2014 and December 31, 2013. In the event of a failed auction, the notes bear interest at a predetermined maximum rate based on the credit rating of notes as determined by one or more nationally recognized statistical rating organizations. For the auction-rate notes held by the Company as of March 31, 2014 and December 31, 2013, the maximum interest rate is generally one month LIBOR plus 1.5% and 2.5%, respectively, based on the notes’ rating as of that date.
	To determine the fair value of financial instruments, the Company uses a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (level 1 measurements) and the lowest priority to unobservable inputs (level 3 measurements). The three levels of the fair value hierarchy are described below:
	•	Level 1 - Quoted prices in active markets for identical assets or liabilities.
	•	Level 2 - Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	•	Level 3 - Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s short-term investments are classified within Level 1 or Level 2 of the fair value hierarchy because they are valued using quoted market prices, broker or dealer quotations, or other significant observable inputs.
	The types of instruments valued based on unobservable inputs consist of the auction-rate notes held by the Company. Such instruments are classified within Level 3 of the fair value hierarchy. The Company estimated the fair value of these auction-rate notes using a discounted cash flow model incorporating assumptions that market participants would use in their estimates of fair value. Some of these assumptions include estimates for interest rates, timing and amount of cash flows and expected holding periods of the auction-rate securities.
	Financial assets measured at fair value on a recurring basis as of March 31, 2014 were as follows (in thousands):
		Quoted Prices in		Significant Other		Significant			Total
		Active Markets		Observable Inputs		Unobservable
		for Identical		Level 2		Inputs
		Assets				Level 3
		Level 1
	Money Market Funds (1)	$	7,150	$	—	$	—		$	7,150
	Corporate Debt Securities (2)	—		37,144		—			37,144
	Commercial Paper (3)	—		13,478		—			13,478
	Municipal Securities (2)	—		15,165		—			15,165
	Auction-rate notes (4)	—		—		4,325			4,325
	Total	$	7,150	$	65,787	$	4,325		$	77,262
	Financial assets measured at fair value on a recurring basis as of December 31, 2013 were as follows (in thousands):
		Quoted Prices in		Significant Other		Significant			Total
		Active Markets		Observable Inputs		Unobservable
		for Identical		Level 2		Inputs
		Assets				Level 3
		Level 1
	Money Market Funds (1)	$	16,945	$	—	$	—		$	16,945
	Corporate Debt Securities (2)	—		36,957		—			36,957
	Commercial Paper (2)	—		13,993		—			13,993
	Municipal Securities (2)	—		13,856		—			13,856
	Auction-rate notes (4)	—		—		4,195			4,195
	Total	$	16,945	$	64,806	$	4,195		$	85,946
	__________
	(1) Included in cash and cash equivalents
	(2) Included in short-term investments
	(3) Included in short-term investments and cash and cash equivalents
	(4) Included in long-term investments
	There were no significant transfers between Level 1 and Level 2 of the fair value hierarchy.
	The Company has used a combination of discounted cash flow models and observable transactions for similar securities to determine the estimated fair value of its investment in auction-rate notes as of March 31, 2014 and December 31, 2013. The assumptions used in preparing the discounted cash flow model include estimates for interest rates, estimates for discount rates using yields of comparable traded instruments adjusted for illiquidity and other risk factors, amount of cash flows and expected holding periods of the auction-rate notes. Based on this assessment of fair value, as of March 31, 2014, the Company determined there was a cumulative decline in the fair value of its auction-rate notes and recorded a $0.2 million net of tax ($0.4 million pre-tax) temporary impairment of these securities to accumulated other comprehensive income, a component of shareholders’ equity.
	For the three months ended March 31, 2014, the changes in the Company’s Level 3 securities (consisting of auction-rate notes) were as follows (in thousands):
		Fair Value
		Measurements
		Using Significant
		Unobservable
		Inputs
		(Level 3)
	Beginning balance, December 31, 2013	$	4,195
	Transfers in and/or out of Level 3	—
Total unrealized gains, before tax, included in other comprehensive income	130
Settlements	—
Ending balance, March 31, 2014	$	4,325

Inventories

Inventories	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
INVENTORIES	'
	INVENTORIES
	Inventories consisted of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Finished goods	$	10,575	$	11,592
	Work in process	30,161		30,109
	Raw materials	1,253		1,500
	Total inventories	$	41,989	$	43,201

Property_Plant_and_Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]	'
PROPERTY, PLANT AND EQUIPMENT	'
	PROPERTY, PLANT AND EQUIPMENT
	Property, plant and equipment consisted of the following (in thousands):
		March 31,			December 31,
		2014			2013
	Manufacturing equipment	$	176,986		$	176,730
	Land	8,101			8,101
	Buildings and improvements	54,214			53,915
	Office furniture and research equipment	18,164			17,791
		257,465			256,537
	Accumulated depreciation	(201,499		)	(198,758		)
	Total property, plant and equipment, net	$	55,966		$	57,779
	Depreciation expense for the three months ended March 31, 2014 and 2013 was $2.7 million and $3.0 million, respectively.

Intangible_Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
INTANGIBLE ASSETS	'
	INTANGIBLE ASSETS
	Intangible Assets
	The Company reviews its purchased intangible assets with finite lives for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. Recoverability of these intangible assets is assessed based on the estimated undiscounted future cash flows expected to result from the use of the asset. If the undiscounted future cash flows are less than the carrying amount, the purchased intangible assets with finite lives are considered to be impaired. The amount of the impairment is measured as the difference between the carrying amount of these assets and the fair value.
	The Company's business combinations have included the purchase of in-process research and development assets that are not amortizable until the underlying project is complete. The Company assesses that its in-process research and development project is complete when all material research and development costs have been incurred and no significant risks remain. The Company reviews the carrying value of indefinite-lived intangible assets for impairment at least annually during the last quarter of its fiscal year, or more frequently if it believes indicators of impairment exist.
	The following table sets forth the components of intangible assets as follows (in thousands):
		31-Mar-14							31-Dec-13
		Gross Carrying Amount		Accumulated Amortization			Net		Gross Carrying Amount		Accumulated Amortization			Net
							Carrying Amount							Carrying Amount
	Developed and core technology	$	7,443	$	(1,192	)	$	6,251	$	7,783	$	(986	)	$	6,797
	Customer relationships	3,800		(756		)	3,044		3,800		(552		)	3,248
	Trademarks	610		(312		)	298		610		(284		)	326
	Non-competition agreements	40		(23		)	17		450		(372		)	78
	In-process research and development	1,300		—			1,300		1,300		—			1,300
		$	13,193	$	(2,283	)	$	10,910	$	13,943	$	(2,194	)	$	11,749
	The above intangible assets acquired in connection with the Discera acquisition in 2013 of $2.8 million, PhaseLink acquisition in 2012 of $8.3 million, and other acquired intangible assets of $2.1 million are amortized over their estimated useful lives ranging from 1 to 10 years using the straight-line method. Total intangible amortization expense for the three months ended March 31, 2014 and 2013 was $0.5 million and $0.3 million, respectively. The Company expects the completion of development projects for Phaselink in 2014 and Discera in 2015 and expects to begin amortizing the related in-process research and development in those respective years.
	The estimated future amortization expense of intangible assets as of March 31, 2014 was as follows (in thousands):
	Year Ending December 31,
	2014 (remaining nine months)	$	1,145
	2015	1,599
	2016	1,510
	2017	1,281
	2018	1,223
	Thereafter	4,152
		$	10,910

Accrued_Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 31, 2014
Accrued Liabilities, Current [Abstract]	'
ACCRUED LIABILITIES	'
	ACCRUED LIABILITIES
	Accrued liabilities consisted of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Accrued compensation	$	6,538	$	5,767
	Accrued commissions	1,590		1,666
	Accrued restructuring	277		902
	Other accrued liabilities	4,938		4,539
	Total accrued liabilities	$	13,343	$	12,874

Borrowing_Arrangements

Borrowing Arrangements	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
BORROWING ARRANGEMENTS	'
	BORROWING ARRANGEMENTS
	Under the terms of an unsecured credit facility with Bank of the West that expires on April 30, 2015, the Company has a $5.0 million line of credit available for general working capital needs, which includes a $5.0 million letter of credit sub-facility including a $2.0 million foreign exchange sub-facility. Interest rates under the facility are based on one of three interest rates, at the Company’s option: (1) a variable alternate base rate plus 1.0%, the alternate base rate being the greater of (x) Bank of the West’s prime rate, (y) the Fed Funds Rate plus 0.5% or (z) daily adjusted one-month LIBOR plus 1.0%; (2) floating one-month LIBOR plus 2.0% or (3) fixed LIBOR for one, two, three or six month periods, plus 2.0%. The credit agreement includes certain restrictive covenants and, as of March 31, 2014, the Company was in compliance with such covenants. As of March 31, 2014, the Company had no borrowings under the line of credit facility.
	The Company's borrowing arrangements include a provision for the issuance of commercial or standby letters of credit by the bank on behalf of the Company. The letters of credit are issued to guarantee payments for the Company's workers compensation program. As of March 31, 2014, there was $0.3 million in letters of credit outstanding.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
DERIVATIVE FINANCIAL INSTRUMENTS	'
	DERIVATIVE FINANCIAL INSTRUMENTS
	During the three months ended March 31, 2014 and 2013, the Company was not party to any derivative instrument arrangements. At March 31, 2014, there were no derivative instrument contracts outstanding.

Major_Customers

Major Customers	3 Months Ended
	Mar. 31, 2014
Risks and Uncertainties [Abstract]	'
MAJOR CUSTOMERS	'
	MAJOR CUSTOMERS
	During the three months ended March 31, 2014, distributors A and B accounted for 28% and 23% of total net revenues, respectively. During the three months ended March 31, 2013, distributors A and B accounted for 31% and 21% of total net revenues, respectively. These distributors sell Micrel's products to many customers across various end markets.
	At March 31, 2014, distributors A, B, and C accounted for 33%, 19%, and 12% respectively, of total accounts receivable. At December 31, 2013, distributors A and B accounted for 36% and 11%, respectively, of total accounts receivable.

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
SEGMENT REPORTING	'
	SEGMENT REPORTING
	The Company currently operates in one segment: the design, manufacturing, marketing and sale of semiconductor products. The chief operating decision maker, the President and CEO, evaluates the financial performance of the Company and allocates resources on a company-wide basis.
	The Company generates revenue from four product groups:  Linear and Power; Timing and Communications; LAN; and Foundry.  The following table sets forth the net revenues attributable to our four product groups as a percentage of total net revenues.
		Three Months Ended
	Net Revenues by Product Group	March 31,
		2014		2013
	Net Revenues:
	Linear and Power	55	%	57	%
	Timing and Communications	22		20
	LAN	20		21
	Foundry	3		2
	Total net revenues	100	%	100	%
	The Company recorded revenue from customers throughout the United States, Canada and Mexico (collectively referred to as “North America”); the United Kingdom, Italy, Germany, France, Israel, Sweden, Hungary, Austria, Finland, Switzerland and other European countries (collectively referred to as “Europe”); Korea, Taiwan, Singapore, China, Japan, Hong Kong, Malaysia and other Asian countries (collectively referred to as “Asia”). Revenues by major geographic area are based on the geographic location of the OEMs or the distributors who have purchased the Company's products. The geographic locations of the Company's distributors may be different from the geographic locations of the end customers.
	The following table sets forth the net revenues by geographic region as a percentage of total net revenues, for the periods presented:
	Net Revenues by Geographic Region	Three Months Ended
		March 31,
		2014		2013
	Net Revenues:
	North America	27	%	31	%
	Asia	57		56
	Europe	16		13
	Total net revenues	100	%	100	%

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
COMMITMENTS AND CONTINGENCIES	'
	COMMITMENTS AND CONTINGENCIES
	From time to time, claims have been filed by or have arisen against the Company in its normal course of business. Generally, litigation is subject to inherent uncertainties, and the Company can provide no assurance that it will prevail in any particular lawsuit. Accordingly, litigation could result in substantial costs and diversion of resources and could have a material adverse effect on the Company’s financial condition, results of operations or cash flows.
	As of March 31, 2014, the Company has not recorded any accrual for contingent liabilities associated with the legal proceedings described above based on the belief that liabilities, while possible, are not probable. Further, ranges of possible losses in these matters cannot be reasonably estimated at this time.

Share_Repurchase_Program

Share Repurchase Program	3 Months Ended
	Mar. 31, 2014
Share Repurchase Program [Abstract]	'
SHARE REPURCHASE PROGRAM	'
	SHARE REPURCHASE PROGRAM
	On October 24, 2013, the Company announced that its Board of Directors authorized the repurchase of $30.0 million of the Company’s common stock, which increased the total approval for repurchase since February 2010 to $120.0 million. Under our stock repurchase program, as of March 31, 2014, we have remaining authorization to repurchase $22.8 million of our common stock.
	Shares of common stock purchased pursuant to the repurchase program are canceled from outstanding shares upon repurchase. Share repurchases are recorded as a reduction to common stock to the extent available. Any amounts repurchased which are in excess of the existing total common stock balance are recorded as a reduction of retained earnings. Share repurchases are intended to reduce the number of outstanding shares of common stock to increase shareholder value and offset dilution from the Company’s stock incentive plans and ESPP. During the three months ended March 31, 2014, the Company repurchased 0.3 million shares of its common stock for an aggregate price of $3.0 million.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	The income tax provision for the three months ended March 31, 2014, as a percentage of income before taxes was 31.3%.
	The income tax provision for the three months ended March 31, 2013, as a percentage of income before taxes, was 4.3%. The income tax provision for this period included a $1.4 million benefit for 2012 research tax credits as a tax law was enacted on January 2, 2013 to retroactively reinstate the federal research and development tax credit to January 1, 2012.
	As of March 31, 2014, the gross amount of unrecognized tax benefits for uncertain tax positions was $13.4 million and the net amount, reduced for the federal effects of potential state tax exposures, was $9.7 million. If these uncertain tax positions are sustained upon tax authority audit, or otherwise become certain, a net $3.8 million would favorably affect the Company’s tax provision in such future periods. The remaining $5.9 million would increase deferred tax assets on which a valuation allowance is placed and would be expected to also increase by a corresponding amount. The $3.8 million liability is included in long-term income taxes payable for $3.7 million and a reduction of prepaid taxes for $0.1 million. The Company does not anticipate a significant change to unrecognized tax benefits for uncertain income tax positions within the next 12 months.
	The Company continues to recognize interest and penalties related to income tax matters as part of the income tax provision. As of March 31, 2014 and December 31, 2013, the Company had $0.4 million and $0.4 million, respectively, accrued for interest and none accrued for penalties in both periods. These accruals are included as a component of long-term income taxes payable.
	The Company is required to file U.S. federal income tax returns as well as income tax returns in various states and foreign jurisdictions. The Company may be subject to examination by the Internal Revenue Service (“IRS”) for calendar years 2010 and forward. Significant state tax jurisdictions include California, Massachusetts and Texas, and generally, the Company is subject to routine examination for years 2006 and forward in these jurisdictions. In addition, any research and development credit carryforwards that were generated in prior years and utilized in these years may also be subject to examination by respective state taxing authorities. Generally, the Company is subject to routine examination for years 2005 and forward in various immaterial foreign tax jurisdictions in which it operates.
	Deferred tax assets and liabilities result primarily from temporary differences between book and tax bases of assets and liabilities and state research and development credit carryforwards. The Company had net current deferred tax assets of $22.3 million and net long-term deferred tax assets of $0.8 million as of March 31, 2014. The Company must regularly assess the likelihood that future taxable income levels will be sufficient to ultimately realize the tax benefits of these deferred tax assets. The Company currently believes that future taxable income levels will be sufficient to realize the tax benefits of these deferred tax assets and has not established a valuation allowance except for a valuation allowance of $9.3 million and $9.0 million that was established against state deferred tax assets as of March 31, 2014 and December 31, 2013, respectively, due to California tax law changes in 2012 which require mandatory single sales factor apportionment in California for most multi-state taxpayers for tax years beginning on or after January 1, 2013. Should the Company determine that future realization of these tax benefits is not more likely than not, additional valuation allowances would be established which would increase the Company's tax provision in the period of such determination.
	Included in net deferred tax assets are credit carryforwards. The Company has available state research and development credit carryforwards of approximately $24.9 million, of which approximately $2.3 million represents pre-ownership change carryforwards subject to Section 382 annual limitation. The state research credit carryforwards are not subject to expiration and may be carried forward indefinitely until utilized.

Dividends

Dividends	3 Months Ended
	Mar. 31, 2014
Dividends, Common Stock [Abstract]	'
DIVIDENDS	'
	DIVIDENDS
	On January 30, 2014, the Company’s Board of Directors declared a cash dividend of $0.05 per share of common stock. The aggregate payment of $2.8 million was made on February 27, 2014 to shareholders of record as of February 13, 2014.

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
RESTRUCTURING CHARGES	'
	RESTRUCTURING CHARGES
	In the fourth quarter of 2013, the Company recorded restructuring charges of $1.4 million related to workforce reductions. The Company paid $0.6 million related to severance costs in the quarter ended March 31, 2014. The following table summarizes the activity related to the accrual for restructuring charges for the quarter ended March 31, 2014 (in thousands):
		Amount
	Balance at December 31, 2013	$	902
	Payments	(625		)
	Balance at March 31, 2014	$	277

Subsequent_Events

Subsequent Events	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]	'
SUBSEQUENT EVENTS	'
	SUBSEQUENT EVENTS
	On April 24, 2014, the Company’s Board of Directors declared a cash dividend of $0.05 per outstanding share of common stock payable on May 22, 2014 to shareholders of record at the close of business on May 8, 2014. This dividend will be recorded in the second quarter of 2014 and is expected to be approximately $2.8 million.

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Interim Financial Information	'
	Interim Financial Information - The accompanying condensed consolidated financial statements of Micrel, Incorporated and its wholly-owned subsidiaries (together “Micrel” or the “Company”) as of March 31, 2014 and for the three months ended March 31, 2014 and 2013 are unaudited. In the opinion of management, the condensed consolidated financial statements include all adjustments (consisting only of normal recurring adjustments) that management considers necessary for a fair statement of its financial position, operating results, comprehensive income and cash flows for the interim periods presented. Operating results and cash flows for interim periods are not necessarily indicative of results for the entire year. The Condensed Consolidated Balance Sheet as of December 31, 2013, was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted (“GAAP”) in the United States of America. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013. These financial statements should also be read in conjunction with the Company’s critical accounting policies included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 and those included in this Form 10-Q below.
Net Income Per Common and Equivalent Share	'
	Net Income Per Share - Basic net income per share is computed by dividing net income by the number of weighted-average common shares outstanding. Diluted net income per share reflects potential dilution from outstanding stock options and restricted stock units ("RSUs") using the treasury stock method. Reconciliation of weighted-average shares used in computing basic and diluted net income per share is as follows (in thousands):
		Three Months Ended
		March 31,
		2014	2013
	Weighted average common shares outstanding	56,388	58,270
	Dilutive effect of stock options and restricted stock units	820	760
	Shares used in computing diluted net income per share	57,208	59,030
	For the three months ended March 31, 2014 and 2013, 4.7 million and 5.3 million shares underlying stock options, respectively, have been excluded from the weighted-average number of common shares outstanding for the diluted net income per share computations as they were anti-dilutive.
Goodwill	'
	Goodwill - Goodwill represents the excess of the purchase price over the fair value of net tangible and identifiable intangible assets acquired. Goodwill is measured and tested for impairment annually at the reporting unit level during the last quarter of the Company’s fiscal year, or more frequently if the Company believes indicators of impairment exist. Events that could trigger a more frequent impairment review may include adverse industry or economic trends, restructuring actions, lower projections of profitability, or a sustained decline in our market capitalization.
	On April 2, 2012, the Company acquired PhaseLink™ Company Limited (“Phaselink”) and recorded $6.1 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets. On September 9, 2013, the Company acquired specific net assets of Discera Inc. (“Discera”) and recorded $2.5 million of goodwill as the purchase price exceeded the fair value allocated to net tangible assets and identifiable intangible assets. During the first quarter of 2014, goodwill recorded from the Discera transaction was increased by approximately $0.1 million to $2.6 million. The goodwill for each acquisition was allocated to the timing and communications reporting unit and is reviewed annually in October or whenever events or circumstances occur which indicate that goodwill might be impaired.

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Reconciliation of weighted-average shares used in computing net income per share	'
	Reconciliation of weighted-average shares used in computing basic and diluted net income per share is as follows (in thousands):
		Three Months Ended
		March 31,
		2014	2013
	Weighted average common shares outstanding	56,388	58,270
	Dilutive effect of stock options and restricted stock units	820	760
	Shares used in computing diluted net income per share	57,208	59,030

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-based compensation expense	'
	The following table summarizes total share-based compensation expense included in the Condensed Consolidated Statement of Operations (in thousands):
		Three Months Ended
		March 31,
		2014				2013
	Cost of revenues	$	234			$	244
	Research and development	690				652
	Selling, general and administrative	798				723
	Pre-tax share-based compensation expense	1,722				1,619
	Less income tax effect	(549		)		(550		)
	Net share-based compensation expense	$	1,173			$	1,069
Stock options granted under the Company's option plans	'
	The fair value of the Company’s stock options granted under the Company’s option plans was estimated at the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions:
		Three Months Ended
		March 31,
		2014			2013
	Expected term (years)	6.1			5.9
	Stock volatility	31	%		33.5	%
	Risk free interest rates	2.1	%		1	%
	Dividends during expected terms	1.8	%		1.6	%

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Summary of short-term investments	'
	A summary of the Company’s short-term investments at March 31, 2014 and December 31, 2013 was as follows (in thousands):
		As of March 31, 2014									As of December 31, 2013
		Cost		Gross Unrealized		Gross Unrealized			Fair		Cost		Gross Unrealized		Gross Unrealized Losses			Fair
				Gains		Losses			Value				Gains					Value
	Municipal Securities	$	15,163	$	2	$	—		$	15,165	$	13,858	$	—	$	(2	)	$	13,856
	Corporate Debt Securities	37,145		—		(1		)	37,144		36,947		10		—			36,957
	Commercial Paper	10,976		1		—			10,977		13,991		2		—			13,993
	Total	$	63,284	$	3	$	(1	)	$	63,286	$	64,796	$	12	$	(2	)	$	64,806
Summary of long-term investments	'
	A summary of the Company’s long-term investments at March 31, 2014 and December 31, 2013 was as follows (in thousands):
		As of March 31, 2014									As of December 31, 2013
		Cost		Gross Unrealized		Gross Unrealized			Fair		Cost		Gross Unrealized		Gross Unrealized			Fair
				Gains		Losses			Value				Gains		Losses			Value
	Auction Rate Notes	$	4,700	$	—	$	(375	)	$	4,325	$	4,700	$	—	$	(505	)	$	4,195
Schedule of financial assets measured at fair value on a recurring basis	'
	Financial assets measured at fair value on a recurring basis as of March 31, 2014 were as follows (in thousands):
		Quoted Prices in		Significant Other		Significant			Total
		Active Markets		Observable Inputs		Unobservable
		for Identical		Level 2		Inputs
		Assets				Level 3
		Level 1
	Money Market Funds (1)	$	7,150	$	—	$	—		$	7,150
	Corporate Debt Securities (2)	—		37,144		—			37,144
	Commercial Paper (3)	—		13,478		—			13,478
	Municipal Securities (2)	—		15,165		—			15,165
	Auction-rate notes (4)	—		—		4,325			4,325
	Total	$	7,150	$	65,787	$	4,325		$	77,262
	Financial assets measured at fair value on a recurring basis as of December 31, 2013 were as follows (in thousands):
		Quoted Prices in		Significant Other		Significant			Total
		Active Markets		Observable Inputs		Unobservable
		for Identical		Level 2		Inputs
		Assets				Level 3
		Level 1
	Money Market Funds (1)	$	16,945	$	—	$	—		$	16,945
	Corporate Debt Securities (2)	—		36,957		—			36,957
	Commercial Paper (2)	—		13,993		—			13,993
	Municipal Securities (2)	—		13,856		—			13,856
	Auction-rate notes (4)	—		—		4,195			4,195
	Total	$	16,945	$	64,806	$	4,195		$	85,946
	__________
	(1) Included in cash and cash equivalents
	(2) Included in short-term investments
	(3) Included in short-term investments and cash and cash equivalents
	(4) Included in long-term investments
Schedule of changes in Level 3 securities	'
	For the three months ended March 31, 2014, the changes in the Company’s Level 3 securities (consisting of auction-rate notes) were as follows (in thousands):
		Fair Value
		Measurements
		Using Significant
		Unobservable
		Inputs
		(Level 3)
	Beginning balance, December 31, 2013	$	4,195
	Transfers in and/or out of Level 3	—
	Total unrealized gains, before tax, included in other comprehensive income	130
	Settlements	—
	Ending balance, March 31, 2014	$	4,325

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories consisted of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Finished goods	$	10,575	$	11,592
	Work in process	30,161		30,109
	Raw materials	1,253		1,500
	Total inventories	$	41,989	$	43,201

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]	'
Property, plant and equipment	'
	Property, plant and equipment consisted of the following (in thousands):
		March 31,			December 31,
		2014			2013
	Manufacturing equipment	$	176,986		$	176,730
	Land	8,101			8,101
	Buildings and improvements	54,214			53,915
	Office furniture and research equipment	18,164			17,791
		257,465			256,537
	Accumulated depreciation	(201,499		)	(198,758		)
	Total property, plant and equipment, net	$	55,966		$	57,779

Intangible_Assets_Tables

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Schedule of Finite-Lived Intangible Assets	'
	The following table sets forth the components of intangible assets as follows (in thousands):
		31-Mar-14							31-Dec-13
		Gross Carrying Amount		Accumulated Amortization			Net		Gross Carrying Amount		Accumulated Amortization			Net
							Carrying Amount							Carrying Amount
	Developed and core technology	$	7,443	$	(1,192	)	$	6,251	$	7,783	$	(986	)	$	6,797
	Customer relationships	3,800		(756		)	3,044		3,800		(552		)	3,248
	Trademarks	610		(312		)	298		610		(284		)	326
	Non-competition agreements	40		(23		)	17		450		(372		)	78
	In-process research and development	1,300		—			1,300		1,300		—			1,300
		$	13,193	$	(2,283	)	$	10,910	$	13,943	$	(2,194	)	$	11,749
Schedule of future amortization expenses	'
	The estimated future amortization expense of intangible assets as of March 31, 2014 was as follows (in thousands):
	Year Ending December 31,
	2014 (remaining nine months)	$	1,145
	2015	1,599
	2016	1,510
	2017	1,281
	2018	1,223
	Thereafter	4,152
		$	10,910

Accrued_Liabilities_Tables

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 31, 2014
Accrued Liabilities, Current [Abstract]	'
Schedule of accrued liabilities	'
	Accrued liabilities consisted of the following (in thousands):
		March 31,		December 31,
		2014		2013
	Accrued compensation	$	6,538	$	5,767
	Accrued commissions	1,590		1,666
	Accrued restructuring	277		902
	Other accrued liabilities	4,938		4,539
	Total accrued liabilities	$	13,343	$	12,874

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2014
Schedule of Segment Revenue by Percent	'
	The following table sets forth the net revenues attributable to our four product groups as a percentage of total net revenues.
		Three Months Ended
	Net Revenues by Product Group	March 31,
		2014		2013
	Net Revenues:
	Linear and Power	55	%	57	%
	Timing and Communications	22		20
	LAN	20		21
	Foundry	3		2
	Total net revenues	100	%	100	%
Net Revenues by Geographic Region by Percent	'
	The following table sets forth the net revenues by geographic region as a percentage of total net revenues, for the periods presented:
	Net Revenues by Geographic Region	Three Months Ended
		March 31,
		2014		2013
	Net Revenues:
	North America	27	%	31	%
	Asia	57		56
	Europe	16		13
	Total net revenues	100	%	100	%

Restructuring_Tables

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2014
Restructuring Cost and Reserve (Line Items)	'
Restructuring and Related Costs	'
	The following table summarizes the activity related to the accrual for restructuring charges for the quarter ended March 31, 2014 (in thousands):
		Amount
	Balance at December 31, 2013	$	902
	Payments	(625		)
	Balance at March 31, 2014	$	277

Significant_Accounting_Policie3

Significant Accounting Policies (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Reconciliation of weighted-average shares used in computing basic and diluted net income per share	'	'
Weighted average common shares outstanding	56,388	58,270
Dilutive effect of stock options and restricted stock units	820	760
Shares used in computing diluted net income per share	57,208	59,030

Significant_Accounting_Policie4

Significant Accounting Policies (Details Textual)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Significant Accounting Policies (Textual) [Abstract]	'	'
Stock options excluded from the weighted-average number of common shares outstanding for the diluted net income per share computations as they were anti-dilutive	4.7	5.3

Significant_Accounting_Policie5

Significant Accounting Policies - Goodwill (Details) (USD $)	Apr. 02, 2012	Mar. 31, 2014	Sep. 09, 2013
In Millions, unless otherwise specified	PhaseLink Acquisition [Member]	Discera, Inc. [Member]	Discera, Inc. [Member]
Goodwill [Line Items]	'	'	'
Goodwill, Gross	$6.10	$2.60	$2.50
Goodwill, Other Changes	'	$0.10	'

ShareBased_Compensation_Detail

Share-Based Compensation (Details Textual) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Share-Based Compensation (Textual) [Abstract]	'	'	'
Stock options granted	0.2	0.2	'
Weighted Average Fair Value of Options Granted	$2.79	$2.91	'
Unrecognized share-based compensation related to non-vested stock option awards	$6.50	'	'
Weighted-average period for unrecognized share-based compensation	'2 years 9 months 18 days	'	'
Total share-based compensation capitalized as part of inventory	0.1	'	0.2
Purchase shares of Common Stock with respect to market value of stock	95.00%	'	'
Restricted Stock Units (RSUs) [Member]	'	'	'
Share-Based Compensation (Textual) [Abstract]	'	'	'
Restricted Stock Units granted	0.2	0.1	'
Weighted average fair values of Restricted Stock Units granted	$9.81	$10.07	'
Unrecognized share-based compensation related to non-vested stock option awards	$9	'	'
Weighted-average period for unrecognized share-based compensation	'3 years 1 month 6 days	'	'

ShareBased_Compensation_Detail1

Share-Based Compensation (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Share-based compensation expense	'	'
Allocated Share-based Compensation Expense	$1,722	$1,619
Less income tax effect	-549	-550
Net share-based compensation expense	1,173	1,069
Cost of revenues [Member]	'	'
Share-based compensation expense	'	'
Allocated Share-based Compensation Expense	234	244
Research and development [Member]	'	'
Share-based compensation expense	'	'
Allocated Share-based Compensation Expense	690	652
Selling, general and administrative [Member]	'	'
Share-based compensation expense	'	'
Allocated Share-based Compensation Expense	$798	$723

ShareBased_Compensation_Detail2

Share-Based Compensation (Details 1)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock options granted under the Company's option plans	'	'
Expected term (years)	'6 years 1 month 15 days	'5 years 10 months 29 days
Stock volatility	31.00%	33.50%
Risk free interest rates	2.10%	1.00%
Dividends during expected terms	1.80%	1.60%

Investments_Details

Investments (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Short Term Investments [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	$63,284	$64,796
Gross Unrealized Gains	3	12
Gross Unrealized Losses	-1	-2
Fair Value	63,286	64,806
Short Term Investments [Member] | Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	37,145	36,947
Gross Unrealized Gains	0	10
Gross Unrealized Losses	-1	0
Fair Value	37,144	36,957
Short Term Investments [Member] | Commercial Paper [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	10,976	13,991
Gross Unrealized Gains	1	2
Gross Unrealized Losses	0	0
Fair Value	10,977	13,993
Short Term Investments [Member] | Municipal Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	15,163	13,858
Gross Unrealized Gains	2	0
Gross Unrealized Losses	0	-2
Fair Value	15,165	13,856
Long Term Investments [Member] | Auction Rate Notes [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Cost	4,700	4,700
Gross Unrealized Gains	0	0
Gross Unrealized Losses	-375	-505
Fair Value	$4,325	$4,195

Investments_Details_1

Investments (Details 1) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	$77,262		$85,946
Corporate Debt Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	37,144	[1]	36,957	[1]
Commercial Paper [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	13,478	[2]	13,993	[1]
Auction rate notes [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	4,325	[3]	4,195	[3]
Money Market Funds [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	7,150	[4]	16,945	[4]
Municipal Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	15,165	[1]	13,856	[1]
Quoted Prices in Active Markets for Identical Assets Level 1 [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	7,150		16,945
Quoted Prices in Active Markets for Identical Assets Level 1 [Member] | Corporate Debt Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets Level 1 [Member] | Commercial Paper [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[2]	0	[1]
Quoted Prices in Active Markets for Identical Assets Level 1 [Member] | Auction rate notes [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[3]	0	[3]
Quoted Prices in Active Markets for Identical Assets Level 1 [Member] | Money Market Funds [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	7,150	[4]	16,945	[4]
Quoted Prices in Active Markets for Identical Assets Level 1 [Member] | Municipal Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[1]	0	[1]
Significant Other Observable Inputs Level 2 [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	65,787		64,806
Significant Other Observable Inputs Level 2 [Member] | Corporate Debt Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	37,144	[1]	36,957	[1]
Significant Other Observable Inputs Level 2 [Member] | Commercial Paper [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	13,478	[2]	13,993	[1]
Significant Other Observable Inputs Level 2 [Member] | Auction rate notes [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[3]	0	[3]
Significant Other Observable Inputs Level 2 [Member] | Money Market Funds [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[4]	0	[4]
Significant Other Observable Inputs Level 2 [Member] | Municipal Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	15,165	[1]	13,856	[1]
Significant Unobservable Inputs Level 3 [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	4,325		4,195
Significant Unobservable Inputs Level 3 [Member] | Corporate Debt Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[1]	0	[1]
Significant Unobservable Inputs Level 3 [Member] | Commercial Paper [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[2]	0	[1]
Significant Unobservable Inputs Level 3 [Member] | Auction rate notes [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	4,325	[3]	4,195	[3]
Significant Unobservable Inputs Level 3 [Member] | Money Market Funds [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	0	[4]	0	[4]
Significant Unobservable Inputs Level 3 [Member] | Municipal Securities [Member]	'		'
Schedule of financial assets measured at fair value on a recurring basis	'		'
Total	$0	[1]	$0	[1]
[1]	Included in short-term investments
[2]	Included in short-term investments and cash and cash equivalents
[3]	Included in long-term investments
[4]	Included in cash and cash equivalents

Investments_Details_Textual

Investments (Details Textual) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Short-term investments, minimum maturity period	'1 month
Short -term investments, maximum maturity period	'2 years
Short-term interest rate reset dates of auction rate note securities	' less than ninety days
Auction rate note securities with contractual maturities	'excess of ten years
Reset period for the securities held	'seven or twenty-eight days
Auction rate notes [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Comprehensive income net of tax due to auction rate notes	0.2
Comprehensive income before tax due to auction rate notes	0.4
Minimum [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Period for principal repayments by issuer	'18 years
Minimum [Member] | Auction rate notes [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Maximum Interest Rate	1.50%
Maximum [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Period for principal repayments by issuer	'34 years
Maximum [Member] | Auction rate notes [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Maximum Interest Rate	2.50%

Investments_Details_2

Investments (Details 2) (Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Member]	'
Schedule of changes in Level 3 securities	'
Beginning balance	$4,195
Transfers in and/or out of Level 3	0
Total unrealized gains before tax, included in other comprehensive income	130
Settlements	0
Ending balance	$4,325

Inventories_Details

Inventories (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventories	'	'
Inventory, Finished Goods, Net of Reserves	$10,575	$11,592
Inventory, Work in Process, Net of Reserves	30,161	30,109
Inventory, Raw Materials, Net of Reserves	1,253	1,500
Total inventories	$41,989	$43,201

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property, plant and equipment	'	'
Property, plant and equipment, Gross	$257,465	$256,537
Accumulated depreciation	-201,499	-198,758
Total property, plant and equipment, net	55,966	57,779
Manufacturing equipment [Member]	'	'
Property, plant and equipment	'	'
Property, plant and equipment, Gross	176,986	176,730
Land [Member]	'	'
Property, plant and equipment	'	'
Property, plant and equipment, Gross	8,101	8,101
Buildings and improvements [Member]	'	'
Property, plant and equipment	'	'
Property, plant and equipment, Gross	54,214	53,915
Office furniture and research equipment [Member]	'	'
Property, plant and equipment	'	'
Property, plant and equipment, Gross	$18,164	$17,791

Property_Plant_and_Equipment_D1

Property, Plant and Equipment (Details Textual) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Property, Plant and Equipment (Textual) [Abstract]	'	'
Depreciation	$2.70	$3

Intangible_Assets_Details_Text

Intangible Assets (Details Textual) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Finite-Lived Intangible Assets [Line Items]	'	'
Amortization of Intangible Assets	$0.50	$0.30
Minimum [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Estimated useful life	'1 year	'
Maximum [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Estimated useful life	'10 years	'
Discera, Inc. [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived Intangible Assets Acquired	2.8	'
PhaseLink Acquisition [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived Intangible Assets Acquired	8.3	'
Other Intangible Assets [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-lived Intangible Assets Acquired	$2.10	'

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	$13,193	$13,943
Accumulated Amortization	-2,283	-2,194
Net Carrying Amount	10,910	11,749
Developed and core technology [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	7,443	7,783
Accumulated Amortization	-1,192	-986
Net Carrying Amount	6,251	6,797
Customer relationships [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	3,800	3,800
Accumulated Amortization	-756	-552
Net Carrying Amount	3,044	3,248
Trademarks [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	610	610
Accumulated Amortization	-312	-284
Net Carrying Amount	298	326
Noncompete agreements [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	40	450
Accumulated Amortization	-23	-372
Net Carrying Amount	17	78
In-process research and development [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Finite-Lived Intangible Assets, Gross	1,300	1,300
Accumulated Amortization	0	0
Net Carrying Amount	$1,300	$1,300

Intangible_Assets_Details_1

Intangible Assets (Details 1) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]	'	'
2014 (remaining nine months)	$1,145	'
2015	1,599	'
2016	1,510	'
2017	1,281	'
2018	1,223	'
Thereafter	4,152	'
Net Carrying Amount	$10,910	$11,749

Accrued_Liabilities_Details

Accrued Liabilities (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Schedule of accrued liabilities	'	'
Accrued compensation	$6,538	$5,767
Accrued commissions	1,590	1,666
Accrued restructuring	277	902
Other accrued liabilities	4,938	4,539
Total accrued liabilities	$13,343	$12,874

Borrowing_Arrangements_Details

Borrowing Arrangements (Details) (USD $)	Mar. 31, 2014
Borrowing Arrangements (Additional Textual) [Abstract]	'
Line of credit available for general working capital needs	$5,000,000
Letter of credit sub-facility	5,000,000
Foreign exchange sub-facility	2,000,000
Amount outstanding on the line of credit	0
Letter of Credit [Member]	'
Borrowing Arrangements (Additional Textual) [Abstract]	'
Letters of credit, outstanding	$300,000

Major_Customers_Details

Major Customers (Details) (Customer Concentration Risk [Member])	3 Months Ended					12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014
	Sales [Member]	Sales [Member]	Sales [Member]	Sales [Member]	Accounts Receivable [Member]	Accounts Receivable [Member]	Accounts Receivable [Member]	Accounts Receivable [Member]	Accounts Receivable [Member]
	Distributor A [Member]	Distributor A [Member]	Distributor B [Member]	Distributor B [Member]	Distributor A [Member]	Distributor A [Member]	Distributor B [Member]	Distributor B [Member]	Distributor C [Member]
Revenue, Major Customer [Line Items]	'	'	'	'	'	'	'	'	'
Concentration risk, percentage	28.00%	31.00%	23.00%	21.00%	33.00%	36.00%	19.00%	11.00%	12.00%

Segment_Reporting_Details

Segment Reporting (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Segment Revenue by Percent	100.00%	100.00%
Linear and Power [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Segment Revenue by Percent	55.00%	57.00%
Timing and Communications [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Segment Revenue by Percent	22.00%	20.00%
LAN [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Segment Revenue by Percent	20.00%	21.00%
Foundry [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Segment Revenue by Percent	3.00%	2.00%

Segment_Reporting_Segment_Repo

Segment Reporting Segment Reporting Geographic Information (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues from External Customers [Line Items]	'	'
Net Revenues by Geographic Region by Percentage	100.00%	100.00%
North America [Member]	'	'
Revenues from External Customers [Line Items]	'	'
Net Revenues by Geographic Region by Percentage	27.00%	31.00%
Asia [Member]	'	'
Revenues from External Customers [Line Items]	'	'
Net Revenues by Geographic Region by Percentage	57.00%	56.00%
Europe [Member]	'	'
Revenues from External Customers [Line Items]	'	'
Net Revenues by Geographic Region by Percentage	16.00%	13.00%

Share_Repurchase_Program_Detai

Share Repurchase Program (Details) (USD $)	0 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Oct. 24, 2013	Mar. 31, 2014
Share Repurchase Program [Abstract]	'	'
Stock Repurchase Program, Additional Authorized Amount	$30	'
Share Repurchase Program, Authorized Amount	120	'
Remaining Authorized Repurchase Amount	'	22.8
Stock Repurchased During Period, Shares	'	0.3
Stock Repurchased During Period, Value	'	$3

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income tax provision as percentage of income before taxes	31.30%	'	'
Percentage of income before taxes	'	4.30%	'
Income tax benefit research and development tax credit	'	$1.40	'
Liability for uncertain tax positions	13.4	'	'
Net liability, reduced for the federal effects of potential state tax exposures	9.7	'	'
Tax provision, included not yet reduced income tax payments	3.8	'	'
Increase in deferred tax assets, uncertain tax positions	5.9	'	'
Long-term uncertain income tax positions	3.7	'	'
Accrued income taxes, current	0.1	'	'
Interest and penalties related to income tax	0.4	'	0.4
Current deferred tax assets	22.3	'	'
Deferred tax liabilities, net, noncurrent	0.8	'	'
Deferred tax valuation allowance	9.3	'	9
State and Local Jurisdiction [Member]	'	'	'
Deferred Tax Assets, Tax Credit Carryforwards, Research	24.9	'	'
Deferred tax Assets, Tax Carryforwards, Research, Pre-Ownership Change	$2.30	'	'

Dividends_Details

Dividends (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Dividends, Common Stock [Abstract]	'	'
Board of Directors declared a cash dividend	$0.05	'
Payments of Ordinary Dividends, Common Stock	$2,814	$0

Restructuring_Details

Restructuring (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]	'	'
Beginning Balance	$902,000	'
Restructuring Charges	'	1,400,000
Payments for Restructuring	-625,000	'
Ending Balance	$277,000	$902,000

Subsequent_Events_Details

Subsequent Events (Details) (Dividend Declared [Member], Subsequent Event [Member], USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Apr. 24, 2014
Dividend Declared [Member] | Subsequent Event [Member]	'	'
Subsequent Event [Line Items]	'	'
Board of Directors declared a cash dividend payable	'	$0.05
Dividends to be paid in second quarter	$2.80	'