Quarterly Financial Summary (Parenthetical) (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011
Quarterly Financial Information [Line Items]
Increases (decreases) in gross profit due to change in method of accounting relating to global pension and OPEB plans	$ 3.0	$ 6.6	$ 3.1	$ (27.3)	$ 2.4	$ 0.4	$ 2.3
Increases (decreases) in net income attributable to Albemarle Corporation due to change in method of accounting relating to global pension and OPEB plans	10.2	12.4	6.2	(53.9)	4.6	0.7	4.5
Increases (decreases) in basic earnings per share due to change in method of accounting relating to global pension and OPEB plans	$ 0.12	$ 0.14	$ 0.07	$ (0.61)	$ 0.05	$ 0.01	$ 0.05
Increases (decreases) in diluted earnings per share due to change in method of accounting relating to global pension and OPEB plans	$ 0.12	$ 0.14	$ 0.07	$ (0.6)	$ 0.05	$ 0.01	$ 0.05
Decrease in restructuring and other charges due to change in method of accounting relating to global pension and OPEB plans	$ (6.5)