Stock-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Amount of stock-based compensation costs and related deferred income tax benefit recognized in the financial statements
Total stock-based compensation costs	$ 14,751	$ 12,585	$ 14,931
Less amount capitalized into qualifying real estate projects	(5,396)	(4,935)	(6,962)
Amount charged to operating expenses	9,355	7,650	7,969
Depreciation expense on capitalized stock-based compensation	827	1,246	602
Total stock-based compensation expense	10,182	8,896	8,571
Deferred income tax benefit	3,671	3,184	2,935
Stock option costs [Member]
Amount of stock-based compensation costs and related deferred income tax benefit recognized in the financial statements
Total stock-based compensation costs	3,101	2,606	6,085
Restricted stock costs [Member]
Amount of stock-based compensation costs and related deferred income tax benefit recognized in the financial statements
Total stock-based compensation costs	10,324	9,979	8,846
Performance Shares [Member]
Amount of stock-based compensation costs and related deferred income tax benefit recognized in the financial statements
Total stock-based compensation costs	$ 1,326	$ 0	$ 0