CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 52,175	$ 77,987
Restricted cash and cash equivalents	3,354	5,354
Accounts and other receivables, net	14,914	12,049
Inventories, net	12,926	11,223
Prepaid expenses and other	838	1,769
Deferred income taxes	4,271	4,271
Total current assets	88,478	112,653
Other assets:
Marketable securities	286,884	179,662
Investment in Kronos Worldwide, Inc.	280,100	323,128
Goodwill	27,156	27,156
Other assets, net	2,345	3,854
Total other assets	596,485	533,800
Property and equipment:
Land	5,138	5,138
Buildings	20,791	20,791
Equipment	57,414	59,010
Construction in progress	2,558	1,442
Property and equipment, gross	85,901	86,381
Less accumulated depreciation	51,611	52,052
Net property and equipment	34,290	34,329
Total assets	719,253	680,782
Current liabilities:
Current maturities of long-term debt		1,000
Accounts payable	6,268	5,363
Accrued and other current liabilities	11,471	12,749
Accrued environmental remediation and related costs	4,657	5,667
Income taxes	6	6
Total current liabilities	22,402	24,785
Noncurrent liabilities:
Long-term debt		17,480
Accrued pension costs	11,189	13,747
Accrued postretirement benefit (OPEB) costs	3,551	3,861
Accrued environmental remediation and related costs	53,356	42,339
Deferred income taxes	189,547	171,915
Other	18,372	18,572
Total noncurrent liabilities	276,015	267,914
NL stockholders’ equity:
Common stock	6,084	6,083
Additional paid-in capital	300,223	300,227
Retained earnings	123,193	163,758
Accumulated other comprehensive loss	(22,184)	(95,253)
Total NL stockholders’ equity	407,316	374,815
Noncontrolling interest in subsidiary	13,520	13,268
Total equity	420,836	388,083
Total liabilities and equity	719,253	680,782
Commitments and contingencies (Notes 13 and 14)