Commitments and Contingencies (Details Textual) (USD $)	3 Months Ended
	Apr. 30, 2013	Jan. 31, 2013
Commitments and Contingencies (Textual) [Abstract]
Debt Instrument, Maturity Date	Mar. 10, 2016
Commitments and Contingencies (Additional Textual) [Abstract]
Unrecognized tax benefits	$ 3,500,000	$ 3,500,000
Long-term debt, maturity date	2016-03
Senior subordinated notes maturity period	10 years
Long-term Debt	410,042,000	410,042,000
Term loan expiration prior to number of days	180 days
Operating Lease Obligations [Member] | Maximum [Member]
Commitments and Contingencies (Textual) [Abstract]
Operating lease agreement expire period	2022
Operating Lease Obligations [Member] | Minimum [Member]
Commitments and Contingencies (Textual) [Abstract]
Operating lease agreement expire period	2013
2016 Tranche B term loans: due March 10, 2016, three-month LIBOR plus 4.00% with a 1.00% LIBOR floor [Member]
Commitments and Contingencies (Textual) [Abstract]
Debt instrument annual rate	5.00%
Commitments and Contingencies (Additional Textual) [Abstract]
Long-term Debt	117,399,000	117,399,000
2016 Extended term loans: due March 10, 2016, three-month LIBOR plus 4.00% [Member]
Commitments and Contingencies (Textual) [Abstract]
Debt instrument annual rate	4.20%
Commitments and Contingencies (Additional Textual) [Abstract]
Long-term Debt	191,101,000	191,101,000
2015 Extended revolving term credit facility due March 10, 2015 at the annual rate of 0.375% [Member]
Commitments and Contingencies (Textual) [Abstract]
Debt instrument annual rate	0.375%
Senior Subordinated Notes: due March 15, 2016, 10.375% [Member]
Commitments and Contingencies (Textual) [Abstract]
Debt Instrument, Maturity Date	Mar. 15, 2016
Debt instrument annual rate	10.375%
Commitments and Contingencies (Additional Textual) [Abstract]
Long-term Debt	$ 101,542,000	$ 101,542,000