Marketable Securities - Reconciliation of Available-for-sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Market value	$ 193,942	$ 311,419
Cost basis	31,698	31,698
Unrealized gains	162,244	279,721
Valhi Common Stock [Member] \| Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Market value	175,350	289,711
Cost basis	24,347	24,347
Unrealized gains	151,003	265,364
TIMET Common Stock [Member] \| Fair Value, Inputs, Level 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Market value	18,592	21,708
Cost basis	7,351	7,351
Unrealized gains	$ 11,241	$ 14,357

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details