Stock-Based Compensation Plans (Narrative) (Details) (USD $)	12 Months Ended				10 Months Ended	12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Employee Stock Option Plan [Member]	Dec. 31, 2002 Non-Employee Director Stock Option Plan [Member]	Dec. 31, 2012 Non-Employee Director Stock Option Plan [Member]	Dec. 31, 2012 Non-Employee Director Stock Option Plan [Member] Amended & Restated Non-employee Director Stock Option Plan [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2003 Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Restricted Stock Plan [Member] Y	Dec. 31, 2009 Restricted Stock Plan [Member]	Dec. 31, 2012 Minimum [Member] Employee Stock Option Plan [Member]	Dec. 31, 2012 Minimum [Member] Restricted Stock Plan [Member]	Dec. 31, 2011 Minimum [Member] Restricted Stock Plan [Member]	Dec. 31, 2010 Minimum [Member] Restricted Stock Plan [Member]	Dec. 31, 2012 Maximum [Member] Employee Stock Option Plan [Member]	Dec. 31, 2012 Maximum [Member] Restricted Stock Plan [Member]	Dec. 31, 2011 Maximum [Member] Restricted Stock Plan [Member]	Dec. 31, 2010 Maximum [Member] Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options available for grant				18,000,000
Options granted net of shares from canceled/expired options				13,366,722	549,240	42,000
Option vesting period						6 months						1 year				5 years
Share Based Compensation Arrangement By Share Based Payment Award, Award Expiration Period												3 years				7 years
Unrecognized compensation cost				$ 17,583,516
Weighted-average period for unrecognized compensation cost expected to be recognized				2 years 1 month 6 days
Shares approved							500,000		1,200,000		2,000,000
Option expiration period, years						10 years
Shares sold to employees during period	102,498	68,630	81,249					1,067,426
ESPP discount rate								85.00%
Weighted average fair value of shares sold								$ 17.19
Restricted period, maximum, in years										10
Shares granted with restriction period	225,730	140,900	117,050							694,770
Restricted period for granted shares, in years										5
Market price													$ 17.27	$ 24.96	$ 17.98		$ 24.45	$ 30.25	$ 29.46
Unearned stock-based compensation										8,601,582
Amortization expense										$ 2,108,583