Share-Based Compensation-Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from compensation expense	$ 1.8	$ 2.3	$ 1.6
Total compensation cost not yet recognized	6.8
Period for recognition	3 years
Fair value of stock options that vested during period	$ 0.8	$ 1.7	$ 1.1
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeiture rate	5.00%
Period until vesting	1 year
Awards outstanding	1,926,451	1,805,829
Value of outstanding awards	$ 8.3
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeiture rate	5.00%	5.00%	5.00%
Award vesting period	3 years
Award expiration period	10 years
Exercise price percent of fair value at grant date	100.00%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeiture rate	5.00%
Awards outstanding	1,273,417	1,096,158
Prior to 2011 | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	5 years
Annual vesting percentage			25.00%
Prior to 2013 | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years