Notes Payable (Tables)

6 Months Ended

Jul. 31, 2014

We may redeem some or all of the 4.00% Debentures for cash on or after April 5, 2016 at the following redemption prices expressed as a percentage of principal, plus any accrued and unpaid interest:



Period	Redemption Price
Beginning on April 5, 2016 and ending on March 31, 2017	101.143	%
Beginning on April 1, 2017 and ending on March 31, 2018	100.571	%
On April 1, 2018 and thereafter	100.000	%

4.00% Debentures due 2031

Debt Instrument

Principal amount, unamortized debt premium (discount), net carrying amount of the liability component, and carrying amount of the equity component

The principal amount, unamortized debt discount, net carrying amount of the liability component, and carrying amount of the equity component of the 4.00% Debentures are as follows:



As of	July 31, 2014			January 31, 2014
Principal amount	$	253,000		$	253,000
Unamortized debt discount	(25,724		)	(28,739		)
Net carrying amount of the liability component	$	227,276		$	224,261
Equity component	$	43,930		$	43,930

Recognized amounts in interest expense in the condensed consolidated statement of operations related to debentures

We recognized the following amounts in interest expense in the condensed consolidated statement of income related to the 4.00% Debentures:



	Three months ended July 31,				Six months ended July 31,
	2014		2013		2014		2013
Interest expense at the contractual interest rate	$	2,530	$	2,530	$	5,060	$	5,060
Amortization of debt discount	$	1,521	$	1,416	$	3,015	$	2,807