Acquisitions Acqusitions 2 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended
	Dec. 31, 2011	Jan. 28, 2010 i2 [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Fair value of JDA common stock issued as merger consideration		$ 167,979
Cash merger consideration		431,775
Total merger consideration to acquire i2 Technologies, Inc.		599,754
Less cash acquired from i2 Technologies		218,348
Cash expended to acquire i2 Technologies, Inc.	$ 0	$ 213,427