Accrued Restructuring (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended								9 Months Ended		24 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 2009 Restructuring [Member]	Dec. 31, 2011 2009 Restructuring [Member]	Dec. 31, 2012 Fourth Quarter 2010 Restructuring [Member]	Dec. 31, 2011 Fourth Quarter 2010 Restructuring [Member]	Dec. 31, 2012 Continuous Computing Restructuring [Member] Positions	Sep. 30, 2012 Lease Abandonment Charges [Member]	Sep. 30, 2012 Third Quarter Restructuring Charges [Member] [Member]	Dec. 31, 2012 Continuous Computing Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 2,000	$ 6,000	$ 3,000	$ 3,667	$ 5,071	$ 1,575						$ 1,658	$ 1,253	$ 5,900
Restructuring Reserve, Accrual Adjustment												0	0
Expenditures												(668)	(1,253)
Restructuring Reserve	4,202			1,188	4,202		0	84	0	218
Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date											117
Business Combination, Acquisition Related Costs				0	3,381	0
Business Combination, Integration Related Costs				1,268	1,334	0
Fair Value Adjustment to Contingent Consideration, less Accretion				(5,052)	194	0
Restructuring and acquisition-related charges, net				$ (117)	$ 9,980	$ 1,575