Accounting Policies (Details 1) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2012	Jan. 31, 2012
The components of accumulated other comprehensive income (loss) ("accumulated OCI")
Unrealized losses on securities	$ 452	$ 445
Unrealized losses on foreign currency translation	1,327	1,558
Unrealized losses on interest rate contracts	185,150	194,928
Total unrealized losses	186,929	196,931
Noncontrolling interest and income tax benefit	(72,590)	(76,471)
Accumulated other comprehensive loss	$ 114,339	$ 120,460