Consideration Transferred to Acquire Novellus (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified		3 Months Ended
	Jun. 04, 2012	Sep. 23, 2012 Novellus Systems Incorporated	Sep. 23, 2012 Novellus Systems Incorporated Stock Option		Sep. 23, 2012 Novellus Systems Incorporated Common Stock	Sep. 23, 2012 Novellus Systems Incorporated Restricted Stock Units
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Lam common stock issued at merger		82,689
Per share price of Lam common stock as of June 4, 2012		$ 35.99
Estimated fair value of Lam equivalent equity			$ 41,412	[1]	$ 2,975,977	$ 9,599	[2]
Estimated purchase price consideration	$ 3,026,988	$ 3,026,988

[1] The fair value of the Lam Research equivalent stock options as of the acquisition date was estimated using the Black-Scholes valuation model. Assumptions used are the same as those for acquired awards as disclosed in Note 11 of Notes to Condensed Consolidated Financial Statements.

[2] The fair value of Lam Research equivalent restricted stock as of the acquisition date was estimated based upon the per share price of Lam Research common stock as of June 4, 2012, and giving effect to the exchange ratio of 1.125.