Commitment and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jan. 31, 2012
Company's future principal contractual obligations
2014	$ 3,384
2015	2,834
2016	2,314
2017	2,199
2018	2,005
Thereafter	2,562
Total	15,298
Credit Facility:
Long-term Debt, Total	410,042	442,765
2014	24,527
2015	24,496
2016	24,496
2017	4,076
2018
Thereafter
Total	77,595
2014	27,911
2015	27,330
2016	26,810
2017	416,317
2018	2,005
Thereafter	2,562
Total	502,935
2016 Tranche B term loans: due March 10, 2016, three-month LIBOR plus 4.00% with a 1.00% LIBOR floor [Member]
Credit Facility:
Long-term Debt, Total	117,399
2016 Extended term loans: due March 10, 2016, three-month LIBOR plus 4.00% [Member]
Credit Facility:
Long-term Debt, Total	191,101	191,101
Senior Subordinated Notes: due March 15, 2016, 10.375% [Member]
Credit Facility:
Long-term Debt, Total	101,542	134,265
Credit Facility [Member] \| 2016 Tranche B term loans: due March 10, 2016, three-month LIBOR plus 4.00% with a 1.00% LIBOR floor [Member]
Credit Facility:
2014
2015
2016
2017	117,399
2018
Thereafter
Long-term Debt, Total	117,399
Credit Facility [Member] \| 2016 Extended term loans: due March 10, 2016, three-month LIBOR plus 4.00% [Member]
Credit Facility:
2014
2015
2016
2017	191,101
2018
Thereafter
Long-term Debt, Total	191,101
Credit Facility [Member] \| Senior Subordinated Notes: due March 15, 2016, 10.375% [Member]
Credit Facility:
2014
2015
2016
2017	101,542
2018
Thereafter
Long-term Debt, Total	$ 101,542

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