Stock-Based Compensation Plans - Securities To Be Issued and Remaining Available For Future Issuance (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
2004 LTIP [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options, warrants and rights	17,376
Weighted-average exercise price of outstanding options, warrants and rights	$ 34.94		$ 35.08
Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column 1)	0
Award vesting period	3 years
Shares cliff vest percentage	33.30%
Remaining period following first vesting commencement date	2 years
Award expiration period	7 years
2005 LTIP [Member] | Restricted stock units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options, warrants and rights	3,053
Weighted-average exercise price of outstanding options, warrants and rights	$ 0.01
Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column 1)	0
Award vesting period	3 years
Shares cliff vest percentage	33.30%
Remaining period following first vesting commencement date	2 years
2005 Directors' Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-qualified stock options granted in total	15,000
2005 Directors' Equity Incentive Plan [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of outstanding options, warrants and rights	$ 0.00		$ 27.03
2007 LTIP [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of outstanding options, warrants and rights	$ 25.62	[1]	$ 25.71	[1]
Award expiration period	7 years
2007 LTIP [Member] | Stock Options, Restricted Stock Units and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options, warrants and rights	202,480	[2]
Weighted-average exercise price of outstanding options, warrants and rights	$ 21.40	[2]
Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column 1)	0	[2]
Award vesting period	3 years
Shares cliff vest percentage	33.30%
Remaining period following first vesting commencement date	2 years
2010 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,115,952
Award vesting period	3 years
Annual award limits to any one participant	100,000
2010 LTIP [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of outstanding options, warrants and rights	$ 32.78	[1]	$ 32.78	[1]
2010 LTIP [Member] | Restricted stock units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares cliff vest percentage	33.30%
Remaining period following first vesting commencement date	2 years
2010 LTIP [Member] | Stock Options, Restricted Stock Units and Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of securities to be issued upon exercise of outstanding options, warrants and rights	204,673	[2]
Weighted-average exercise price of outstanding options, warrants and rights	$ 1.21	[2]
Number of securities remaining available for future issuance under equity compensation plans (excluding securities reflected in column 1)	370,271	[2]

[1] The 2007 and 2010 LTIPs are for officers, employees and non-employee directors.

[2] Includes non-qualified stock options, restricted stock units and performance shares.