Share-based Compensation (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		1 Months Ended		3 Months Ended			1 Months Ended			1 Months Ended	3 Months Ended
	Mar. 31, 2013 Restricted Stock	Mar. 31, 2013 Stock Options	Apr. 30, 2012 Selected Officers and Employees Restricted Stock	Mar. 31, 2013 Selected Officers and Employees Restricted Stock	Mar. 31, 2013 Selected Officers and Employees Restricted Stock Minimum	Mar. 31, 2013 Selected Officers and Employees Restricted Stock Maximum	Mar. 31, 2013 Selected Officers and Employees Stock Options	Apr. 30, 2012 Directors Restricted Stock	Mar. 31, 2013 Directors Restricted Stock	Mar. 31, 2013 Directors Stock Options	Jul. 31, 2010 Directors Common Stock	Mar. 31, 2013 Directors Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated forfeiture rate (as a percentage)				4.00%			9.45%		2.00%	5.45%
Estimated annual forfeiture rate (as a percentage)				0.80%			1.89%		0.40%	1.09%
Unrecognized compensation costs	$ 1,348	$ 1
Unrecognized compensation costs, weighted-average period of recognition	4 years 0 months 11 days
Award vesting period					1 year	7 years		5 years
Shares granted			298,746
Commitment for future grants in April 2013 for selected non-management employees			81,900
Authorized shares to be reserved for issuance in lieu of cash											1,000,000
Minimum percentage of compensation allowed in shares											50.00%
Shares granted to directors in lieu of fees												3,118