Long-term Equity-based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	12 Months Ended						0 Months Ended	36 Months Ended	0 Months Ended	36 Months Ended		1 Months Ended	36 Months Ended
	May 02, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Performance Based Restricted Stock [Member]	Dec. 31, 2013 Options Granted Prior to May 1, 2013 [Domain]	Dec. 31, 2013 Performance Period, 2012 to 2014 [Member] Performance Based Restricted Stock [Member]	Feb. 01, 2014 Performance Period, 2011 to 2013 [Member] Performance Based Restricted Stock [Member]	Dec. 31, 2013 Performance Period, 2011 to 2013 [Member] Performance Based Restricted Stock [Member]	Feb. 02, 2013 Performance Period, 2010 to 2012 [Member] Performance Based Restricted Stock [Member]	Dec. 31, 2012 Performance Period, 2010 to 2012 [Member] Performance Based Restricted Stock [Member]	Dec. 31, 2013 Performance Period, 2013 to 2015 [Member] Performance Based Restricted Stock [Member]	Jan. 31, 2012 Performance Period, 2009 to 2011 [Member] Performance Based Restricted Stock [Member]	Dec. 31, 2011 Performance Period, 2009 to 2011 [Member] Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual Awards of Deferred Stock Units to be Issued to each Non-Employee Director	500
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized		10,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		8,750,768
Reduction in Share Authorization if Maximum Performance Level is Met or Exceeded					390,486		179,325					180,450
Allocated Share-based Compensation Expense		$ 5.5	$ 5.8	$ 5.3
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized		$ 5.4
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition		1 year 4 months 24 days
Share-based Compensation,Initial Grant For Non-Employee Director, Shares		4,000
Share Based Compensation Arrangement By Share Based Payment Award, Automatic Annual Grant, Non-Employee Directors, Options		4,000
Share Based Compensation Arrangement By Share Based Payment Award, Automatic Annual Grant, Non-Employee Directors, Options, Vesting Period						1 year
Share Based Compensation Arrangement By Share Based Payment Award, Automatic Annual Grant, Non-Employee Directors, Options, Expiration Date						10 years
Performance Period					3 years
Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded							59,775					60,150
Payout Percentage for Exceeding Performance Target									118.00%		114.00%			183.00%
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures								9,014		6,996			40,727
Deferred Stock Units Issued	4,000
Fair Value per Deferred Stock Unit Issued	$ 31.50