Financial instruments

12 Months Ended

Dec. 31, 2012

Financial instruments

Note 20—Financial instruments:

The following table summarizes the valuation of our short-term investments and marketable securities, all classified as a noncurrent asset, by the ASC Topic 820 categories as of December 31, 2011 and 2012:

	Fair Value Measurements
	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	(in millions)
December 31, 2011—
Marketable securities	$	311.4	$	311.4		—		—
December 31, 2012 —
Marketable securities		179.7		179.7		—		—

The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure as December 31, 2011 and 2012:

	December 31, 2011				December 31, 2012
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(in millions)
Cash and cash equivalents, restricted cash equivalents and current marketable securities	$	16.5	$	16.5	$	85.0	$	85.0
CompX promissory note payable to TFMC		22.2		22.2		18.5		18.5
CompX bank credit facility		2.0		2.0		—		—
Promissory note payable		9.0		9.0		—		—
Noncontrolling interest in CompX common stock		11.0		24.0		13.3		23.4
NL stockholders’ equity		415.0		631.2		374.8		557.3

The fair value of our noncurrent marketable securities, noncontrolling interest in CompX and NL stockholder’s equity are based upon quoted market prices at each balance sheet date, which represent Level 1 inputs as defined by ASC Topic 820-10-35. The fair value of our promissory notes payable and our variable interest rate debt represent Level 2 inputs and are deemed to approximate book value. Due to their near-term maturities, the carrying amounts of accounts receivable and accounts payable are considered equivalent to fair value.