Incentive Compensation Plan (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Fund made available under the bonus pool	$ 2.5
Compensation paid in cash	0.5
Compensation paid in restricted stock	2.0
Vesting period, minimum (in years)	three
Vesting period, maximum (in years)	five
Vesting Period Three Years [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation paid in restricted stock	0.1
Vesting Period Five Years [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Compensation paid in restricted stock	$ 1.9