Equity (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified			0 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	May 25, 2011 Public Offering [Member]	May 25, 2011 Underwriters Option [Member]
Stockholders Equity Note [Line Items]
Stock offering			3,000,000	450,000
Offering price per share			$ 27.75
Net proceeds from the sale of stock aggregated			$ 79,467	$ 11,957
Underwriters' commission and public offering expenses			$ 245
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	27,387,715	27,124,276