CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 95,230	$ 96,462
Restricted cash and cash equivalents	3,610	3,246
Accounts and other receivables, net	12,121	8,977
Inventories, net	14,419	15,098
Prepaid expenses and other	1,658	981
Total current assets	127,038	124,764
Other assets:
Marketable securities	16,960	19,260
Investment in Kronos Worldwide, Inc.	138,515	140,695
Goodwill	27,156	27,156
Other assets, net	3,543	3,331
Deferred income taxes	11	11
Total other assets	186,185	190,453
Property and equipment:
Land	5,138	5,138
Buildings	21,502	21,502
Equipment	64,751	64,051
Construction in progress	2,115	1,567
Property and equipment, gross	93,506	92,258
Less accumulated depreciation	59,080	58,152
Net property and equipment	34,426	34,106
Total assets	347,649	349,323
Current liabilities:
Accounts payable	4,740	4,557
Accrued and other current liabilities	7,540	10,783
Accrued environmental remediation and related costs	11,431	8,668
Total current liabilities	23,711	24,008
Noncurrent liabilities:
Accrued pension costs	14,010	14,155
Accrued postretirement benefits (OPEB) costs	2,674	2,773
Accrued environmental remediation and related costs	104,234	104,465
Deferred income taxes	25,020	25,035
Other	13,608	13,636
Total noncurrent liabilities	159,546	160,064
NL stockholders' equity:
Common stock	6,086	6,086
Additional paid-in capital	300,543	300,543
Retained earnings	86,210	88,679
Accumulated other comprehensive loss	(243,954)	(245,358)
Total NL stockholders' equity	148,885	149,950
Noncontrolling interest in subsidiary	15,507	15,301
Total equity	164,392	165,251
Total liabilities and equity	$ 347,649	$ 349,323
Commitments and contingencies (Notes 11 and 13)