Stockholders' Equity (Share-Based Payments - Options and Stock Appreciation Rights Outstanding) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available For Grant, Exercised	0
Shares Available For Grant, Forfeited	0
Shares Available For Grant, Expired	0
Shares Available For Grant, Granted	0
Shares Available For Grant, Ending Balance	291,000
Shares/Awards [Roll Forward]
Options Outstanding, Shares, Beginning Balance	36,668
Options Outstanding, Shares, Exercised	(6,400)
Options Outstanding, Shares, Forfeited	(500)
Options Outstanding, Shares, Granted	0
Options Outstanding, Shares, Expired	0
Options Outstanding, Shares, Ending Balance	29,768	36,668
Weighted-Average Exercise Price [Roll Forward]
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 229.24
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 165.64
Options Outstanding, Weighted-Average Exercise Price, Forfeited	$ 255.13
Options Outstanding, Weighted-Average Exercise Price, Expired	$ 0.00
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 0.00
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	$ 242.48	$ 229.24
Total intrinsic value of options exercised	$ 1.1	$ 2.5
Total intrinsic value of options exercised	1.1	2.5
Total fair value of shares vested	0.2	0
Total fair value of shares vested	$ 1.1	$ 0.7
Stock Appreciation Rights (SARs) [Member]
Shares/Awards [Roll Forward]
Options Outstanding, Shares, Beginning Balance	99,461
Options Outstanding, Shares, Exercised	(3,425)
Options Outstanding, Shares, Forfeited	(3,850)
Options Outstanding, Shares, Granted	0
Options Outstanding, Shares, Ending Balance	92,186
Weighted-Average Exercise Price [Roll Forward]
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 156.93
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 119.87
Options Outstanding, Weighted-Average Exercise Price, Forfeited	$ 171.27
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 0.00
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	$ 157.71