Changes in accumulated other comprehensive income (loss) attributable to NL stockholders, including amounts resulting from our investment in Kronos Worldwide (see Note 5), are presented in the table below.

	Three months ended
	March 31,
	2017			2018
	(In thousands)
Accumulated other comprehensive loss, net of tax:
Marketable securities:
Balance at beginning of period	$	20,473		$	46,069
Change in accounting principle		—			(46,069	)
Balance at beginning of period, as adjusted		20,473			—
Other comprehensive income - unrealized gains (losses) arising during the year		(1,722	)		—

Balance at end of period	$	18,751		$	—

Currency translation:
Balance at beginning of period	$	(175,859	)	$	(164,467	)
Other comprehensive income		1,771			2,591

Balance at end of period	$	(174,088	)	$	(161,876	)

Interest rate swap:
Balance at beginning of period	$	(390	)	$	—
Other comprehensive income:
Unrealized gains arising during the year		1			—
Less reclassification adjustment for amounts included in interest expense		111			—

Balance at end of period	$	(278	)	$	—

Defined benefit pension plans:
Balance at beginning of period	$	(76,710	)	$	(72,951	)
Other comprehensive income - amortization of net losses included in net periodic pension cost		867			983

Balance at end of period	$	(75,843	)	$	(71,968	)

OPEB plans:
Balance at beginning of period	$	(360	)	$	(388	)
Other comprehensive loss - amortization of net gains included in net periodic OPEB cost		(48	)		(73	)

Balance at end of period	$	(408	)	$	(461	)

Total accumulated other comprehensive loss:
Balance at beginning of period	$	(232,846	)	$	(191,737	)
Change in accounting principle		—			(46,069	)
Balance at beginning of period, as adjusted		(232,846	)		(237,806	)
Other comprehensive income		980			3,501

Balance at end of period	$	(231,866	)	$	(234,305	)