Stock-Based Compensation Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Achieves a specified improvement in total shareholder return at the end of 2016 compared to 2011 and she remains an employee [Member] | Common Stock [Member] | Chairman, President, and Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	135,000
Achieves a specified improvement in total shareholder return at the end of 2014 compared to 2011 and she remains an employee [Member] | Common Stock [Member] | Chairman, President, and Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	35,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options, Outstanding at beginning of period, Shares	1,992,700
Options, Outstanding at beginning of period, Weighted-Average Exercise Price, in dollars per share	$ 20.72
Options, Granted, Shares	0
Options, Granted, Weighted-Average Exercise Price, in dollars per share	$ 0.00
Options, Exercised, Shares	(319,239)
Options, Exercised, Weighted-Average Exercise Price, in dollars per share	$ 14.47
Options, Forfeited, Shares	0
Options, Forfeited, Weighted-Average Exercise Price, in dollars per share	$ 0.00
Options, Expired, Shares	(329,795)
Options, Expired, Weighted-Average Exercise Price, in dollars per share	$ 27.17
Options, Outstanding at end of period, Shares	1,343,666	1,992,700
Options, Outstanding at end of period, Weighted-Average Exercise Price, in dollars per share	$ 20.63	$ 20.72
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options, Outstanding at end of period, Aggregate Intrinsic Value	$ 7,300,000
Options, Outstanding at end of period, Weighted-Average Remaining Contract Life (years)	3 years 5 months 5 days
Options, Outstanding at end of period, No intrinsic value	509,916,000
Weighted-average grant date fair value options granted, in dollars per share	$ 0.00	$ 0.00	$ 0.00
Total fair value of options that vested	625,000	1,054,000	1,189,000
Total intrinsic value of options exercised	2,721,000	6,356,000	2,616,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Restricted Stock, at Beginning of period, Shares	353,722
Restricted Stock, at Beginning of period, Weighted-Average Grant-Date Fair Value, in dollars per share	$ 14.03
Restricted Stock, Granted, Shares	249,113
Restricted Stock, Vested, Shares	(275,988)
Restricted Stock, Vested, Weighted-Average Grant-Date Fair Value, in dollars per share	$ 15.92
Restricted Stock, Forfeited, Shares	(11,542)
Restricted Stock, Forfeited, Weighted-Average Grant-Date Fair Value, in dollars per share	$ 18.39
Restricted Stock, at end of period, Shares	315,305	353,722
Restricted Stock, at end of period, Weighted-Average Grant-Date Fair Value, in dollars per share	$ 17.87	$ 14.03
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Weighted-average grant date fair value	$ 20.03	$ 16.75	$ 13.79
Total fair value of restricted shares that vested (in thousands)	$ 4,395,000	$ 5,099,000	$ 1,240,000
Performance Shares [Member] | Executive [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Excluded from Shares Outstanding, Number	112,864	100,593
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares in 2013	198,369
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares in 2014	179,811