Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Deferred tax asset related to loss carryforwards	$ 28,914,000	$ 27,048,000
Unrecognized tax benefits affecting effective tax rate	40,600,000
Interest and penalties associated with unrecognized tax benefits (Operations)	1,800,000
Interest and penalties associated with unrecognized tax benefits (Balance Sheet)	24,300,000
Wisconsin Research And Development Credit [Member]
Income Taxes [Line Items]
Research and development credit carryforwards	2026
Wisconsin research and development credit carryforwards	9,200,000
Operating Loss Carryforward Expiring 2031 [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	431,700,000
Net operating loss carryforward, expiration dates	2031
Deferred tax asset related to loss carryforwards	28,200,000
Net operating loss carryforwards, valuation allowance	14,200,000
Capital Loss Carryforward Expiring Between 2012 And 2013 [Member]
Income Taxes [Line Items]
Net capital loss carryforwards	2,000,000
Net capital loss carryforward, expiration dates	between 2012 and 2013
Deferred tax assets related to capital loss-carryforwards	700,000
Net capital loss carryforwards, valuation allowance	$ 700,000