Commitments and Contingencies (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Loss Contingencies [Line Items]
Total recorded provisions for Michigan, Massachusetts and a separate unrelated matter			$ 24,200,000
Litigation And Other Professional Fees	23,103,000	6,742,000	19,816,000	6,013,000	42,111,000	36,731,000	29,361,000	5,506,000	55,674,000	113,709,000	77,449,000
Settlement date									September 15, 2010
Cumulative Payments of Relator's expenses and attorneys' fees for Michigan and Massachusetts Settlement	385,000								385,000
Repack Matters SGA [Member]
Loss Contingencies [Line Items]
Increased Costs as a result of Repack Matters									(10,500,000)	(1,200,000)	(1,100,000)
Michigan settlement agreement [Member]
Loss Contingencies [Line Items]
Payments for Legal Settlements										11,600,000
Massachusetts settlement agreement [Member]
Loss Contingencies [Line Items]
Payments for Legal Settlements										$ 9,450,000