Common Stock (Options) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012 $0.01-5.00 [Member]	Dec. 31, 2012 5.01-10.00 [Member]	Dec. 31, 2012 10.01-15.00 [Member]	Dec. 31, 2012 15.01-20.00 [Member]	Dec. 31, 2012 20.01-25.00 [Member]	Dec. 31, 2012 25.01-30.00 [Member]	Dec. 31, 2012 30.01-35.00 [Member]	Dec. 31, 2012 35.01-40.00 [Member]	Dec. 31, 2012 40.01-45.00 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum					$ 0.01	$ 5.01	$ 10.01	$ 15.01	$ 20.01	$ 25.01	$ 30.01	$ 35.01	$ 40.01
Range of Exercise Prices, Maximum					$ 5.00	$ 10.00	$ 15.00	$ 20.00	$ 25.00	$ 30.00	$ 35.00	$ 40.00	$ 45.00
Amount Outstanding	1,288	1,536	3,353	2,782	297	431	121	131	24	149	84	0	51
Weighted Average Remaining Contractual Life					6 years 2 months	7 years 2 months	6 years 0 months	5 years 3 months	4 years 3 months	7 years 2 months	8 years 0 months	0 years	9 years 1 month 6 days
Weighted Average Exercise Price	$ 13.69	$ 9.30	$ 14.30	$ 15.40	$ 3.38	$ 8.37	$ 14.09	$ 16.14	$ 22.97	$ 25.85	$ 31.96	$ 0.00	$ 41.25
Amount Exercisable	770	674	1,932		297	165	105	87	24	62	30	0	0
Weighted Average Exercise Price	$ 10.97	$ 10.14	$ 19.98		$ 3.38	$ 8.34	$ 14.21	$ 16.61	$ 22.97	$ 26.12	$ 32.13	$ 0.00	$ 0.00