Share-Based Payment Plans (Summary of Share-Based Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Restricted stock expense	$ 1,403	$ 1,443	$ 4,602	$ 4,149
Stock option expense	243	367	794	1,078
Employee stock purchase plan discount	3	3	10	11
Total equity-based expense	1,649	1,813	5,406	5,238
Restricted stock classified as liability	17	20	34	40
Total expense	1,666	1,833	5,440	5,278
Less amount capitalized	(72)	(67)	(226)	(190)
Net share-based compensation expense	$ 1,594	$ 1,766	$ 5,214	$ 5,088