Employee Benefit Plans - Other Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2010 Executive Plan [Member]		Dec. 31, 2009 Executive Plan [Member]		Dec. 31, 2011 Directors’ Medical Plan [Member]	Dec. 31, 2010 Directors’ Medical Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total obligation	$ 7.5	[1]	$ 9.3	[1]	$ 0.4	$ 0.3
Cash surrender of insurance policies	$ (2.2)	[2]	$ (2.2)	[2]

[1] Recorded in "Other Long-Term Liabilities" in the Consolidated Balance Sheets.

[2] Recorded in "Other assets, net" in the Consolidated Balance Sheets.