Net Income Per Share (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of weighted-average shares used in computing net income per share
Weighted average common shares outstanding	57,803,000	59,623,000	61,609,000
Dilutive effect of stock options outstanding using the treasury stock method	703,000	665,000	762,000
Shares used in computing diluted net income per share attributable to Micrel Incorporated shareholders	58,506,000	60,288,000	62,371,000
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	5,400,000	5,200,000	4,100,000