Income Taxes (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012		Oct. 31, 2013	Oct. 31, 2012
Income Tax Disclosure [Abstract]
Effective tax rate	35.10%	24.30%		37.50%	28.00%
Decrease in income tax provision	44.90%			21.80%
Provision for income taxes	$ 20,440	$ 14,106	[1]	$ 42,068	$ 53,798
Effective tax rate reconciliation, percentage				35.00%

[1] See Note 2 - Restatement of Consolidated Financial Statements.