Share-Based Compensation (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based compensation incurred	$ 2,339	$ 1,859	$ 5,171	$ 4,048
Capitalized share-based compensation	(223)	(176)	(453)	(358)
Share-based compensation expense	2,116	1,683	4,718	3,690
Restricted Stock [Member]
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based compensation incurred	2,216	1,651	4,890	3,586
Stock Options [Member]
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-based compensation incurred	$ 123	$ 208	$ 281	$ 462