Income Taxes Significant Differences Between U.S. Federal Statutory Rate and Effective Income Tax Rate Footnote (Detail) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jan. 12, 2015
Schedule Of Effective Tax Rates Line Items
Foreign earnings repatriated			$ 308.4	$ 1,400.0	$ 12.6
Effective income tax rate reconciliation, repatriation of foreign earnings, amount			$ 67.5	$ 350.2	$ 2.8
Effective income tax rate reconciliation, foreign income tax rate differential, percent	[1]		19.30%	22.00%	24.80%
Net benefit from release of tax reserves		$ 43.1		$ 42.7	$ 2.5
Jordan Bromine Company Limited
Schedule Of Effective Tax Rates Line Items
Effective income tax rate reconciliation, foreign income tax rate differential, percent			7.30%	8.20%	12.40%
Rockwood Holdings, Inc.
Schedule Of Effective Tax Rates Line Items
Foreign earnings repatriated				$ 111.0
Effective income tax rate reconciliation, repatriation of foreign earnings, amount				327.9
Deferred tax liabilities, undistributed foreign earnings						$ 387.0
Reversal of deferred tax liability, undistributed foreign earnings, impact on earnings				356.2
Reversal of deferred tax liability, undistributed foreign earnings, foreign exchange				$ 30.8

[1] During 2016, 2015 and 2014, we received actual and deemed distributions of $308.4 million, $1.4 billion and $12.6 million, respectively, from various foreign subsidiaries and joint ventures, and realized an expense, net of foreign tax credits, of $67.5 million, $350.2 million and $2.8 million, respectively, related to the repatriation of these earnings, which impacted our effective tax rate. Our statutory rate is decreased by of our share of the income of JBC, a Free Zones company under the laws of the Hashemite Kingdom of Jordan. The applicable provisions of the Jordanian law, and applicable regulations thereunder, do not have a termination provision and the exemption is indefinite. As a Free Zones company, JBC is not subject to income taxes on the profits of products exported from Jordan, and currently, substantially all of the profits are from exports. This gave us a rate benefit of 7.3%, 8.2%, and 12.4% for 2016, 2015, and 2014, respectively.