Debt (Details 1) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jan. 31, 2013
Carrying Amount [Member] | 2016 Tranche B Term Loan [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Carrying Amount Disclosure	$ 117,399
Carrying Amount [Member] | 2013 Tranche B Term Loan [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Carrying Amount Disclosure		117,399
Carrying Amount [Member] | Extended Term Loans [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Carrying Amount Disclosure	191,101	191,101
Carrying Amount [Member] | Senior Subordinated Notes [Member]
Estimated fair values of long-term debt obligations
Notes Payable, Carrying Amount Disclosure	101,542	101,542
Fair Value [Member] | 2016 Tranche B Term Loan [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Fair Value Disclosure	115,932
Fair Value [Member] | 2013 Tranche B Term Loan [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Fair Value Disclosure		118,432
Fair Value [Member] | Extended Term Loans [Member]
Estimated fair values of long-term debt obligations
Loans Payable, Fair Value Disclosure	188,712	191,827
Fair Value [Member] | Senior Subordinated Notes [Member]
Estimated fair values of long-term debt obligations
Notes Payable, Fair Value Disclosure	$ 101,034	$ 103,959