Senior and Subordinated Debt (Tables)

3 Months Ended

Apr. 30, 2013

Debt Disclosure [Abstract]

Schedule of senior and subordinated debt

The following table summarizes the Company’s senior and subordinated debt:

	April 30, 2013		January 31, 2013
	(in thousands)
Senior Notes:
3.625% Puttable Equity-Linked Senior Notes due 2014, net of discount	$	61,006	$	199,457
7.625% Senior Notes due 2015	—		53,253
5.000% Convertible Senior Notes due 2016	50,000		50,000
6.500% Senior Notes due 2017	132,144		132,144
4.250% Convertible Senior Notes due 2018	350,000		350,000
7.375% Senior Notes due 2034, net of discount	219,185		219,115
Total Senior Notes	812,335		1,003,969
Subordinated Debt:
Subordinate Tax Revenue Bonds due 2013	29,000		29,000
Total Senior and Subordinated Debt	$	841,335	$	1,032,969