Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Income Statement [Abstract]
NET REVENUES	$ 62,928		$ 64,244		$ 187,778		$ 200,248
COST OF REVENUES	29,661	[1]	28,567	[1]	86,201	[1]	86,797	[1]
GROSS PROFIT	33,267		35,677		101,577		113,451
OPERATING EXPENSES:
Research and development	15,341	[1]	12,637	[1]	42,585	[1]	37,389	[1]
Selling, general and administrative	11,847	[1]	10,985	[1]	35,186	[1]	34,748	[1]
Total operating expenses	27,188		23,622		77,771		72,137
INCOME FROM OPERATIONS	6,079		12,055		23,806		41,314
OTHER INCOME (EXPENSE):
Interest income	166		186		554		553
Interest expense	47		0		0		(18)
Other income (expense), net	2		66		(121)		141
Total other income, net	215		252		433		676
INCOME BEFORE INCOME TAXES AND NONCONTROLLING INTEREST	6,294		12,307		24,239		41,990
PROVISION FOR INCOME TAXES	1,600		3,095		8,098		12,992
NET INCOME	4,694		9,212		16,141		28,998
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST	(9)				(13)
NET INCOME ATTRIBUTABLE TO MICREL, INCORPORATED SHAREHOLDERS	$ 4,685		$ 9,212		$ 16,128		$ 28,998
NET INCOME PER SHARE ATTRIBUTABLE TO MICREL, INCORPORATED SHAREHOLDERS:
Basic (Per Share)	$ 0.08		$ 0.15		$ 0.27		$ 0.47
Diluted (Per Share)	$ 0.08		$ 0.15		$ 0.27		$ 0.46
CASH DIVIDENDS DECLARED PER SHARE	$ 0.04		$ 0.040		$ 0.12		$ 0.110
WEIGHTED AVERAGE SHARES USED IN COMPUTING PER SHARE AMOUNTS:
Basic (Shares)	59,242		62,043		60,096		62,017
Diluted (Shares)	59,889		62,465		60,774		62,850

[1] Share-based compensation expense included in:Cost of revenues$274 $246 $840 $772Research and development646 615 2,203 1,666Selling, general and administrative719 629 2,287 1,737