Employee Benefit Plans Pension and Other Postretirement Benefits (Details) (USD $)	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Current Liabilities	$ 4,325,000	$ 5,051,000
Pension/postretirement benefit obligations	524,218,000	268,112,000
Health Care Cost Trend Rate	4.75%
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	6,200,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	4,200,000
Deferred Compensation Arrangement with Individual, Recorded Liability	27,087,000	27,828,000
Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Average Compensation Term Of Employment	five years of the last 10 years
Years of Service	10 years
Excess Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Years of Service	10 years
SRIP
Defined Benefit Plan Disclosure [Line Items]
Years of Service	10 years
EPSRS [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	3,075,000	3,925,000	0
Retirement Savings Feature of EPSRS [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	7,735,000	7,088,000	7,278,000
Employees Contribution Percentage	50.00%
Percentage Of Matching Contribution Made By Company Of First Six Percentage Of Participating Employees Contribution	50.00%
Percentage Of Participating Employees Contribution Fifty Percent Matched By Employer	6.00%
Employee Profit Sharing and Retirement Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Percent Investment In Company Stock	26.00%
DCRB Feature of EPSRS Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	4,584,000	3,640,000	3,387,000
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer Contribution	$ 2,758,000	$ 32,767,000
Equity Securities [Member] | Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Plan Asset Allocations Range Minimum	60.00%
Target Plan Asset Allocations Range Maximum	70.00%
Debt Securities [Member] | Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Plan Asset Allocations Range Minimum	20.00%
Target Plan Asset Allocations Range Maximum	30.00%
Other Investments [Member] | Qualified Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Plan Asset Allocations Range Minimum	5.00%
Target Plan Asset Allocations Range Maximum	15.00%
Pre-age 65 [Member]
Defined Benefit Plan Disclosure [Line Items]
Health Care Cost Trend Rate Assumed for Next Fiscal Year	7.50%
Post-age 65 [Member]
Defined Benefit Plan Disclosure [Line Items]
Health Care Cost Trend Rate Assumed for Next Fiscal Year	6.50%