Share-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 plan	Mar. 31, 2013	Mar. 31, 2014 Stock Awards [Member]	Dec. 31, 2013 Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share-based compensation plans	2
Number of shares authorized under plan	10,400,000
Share-based compensation expense	$ 1,916	$ 1,396
Share-based compensation cost capitalized as part of real estate assets	46	50
Unrecognized compensation cost related to nonvested stock awards	$ 9,589
Compensation cost to be recognized over a weighted average period	4 years 0 months
Nonvested, beginning of period (in shares)			550,136	478,216
Granted (in shares)			236,450
Vested (in shares)			(164,090)
Forfeited (in shares)			(440)
Nonvested, end of period (in shares)			550,136	478,216
Weighted average grant date fair value, nonvested, beginning of period (in dollars per share)			$ 18.32	$ 18.72
Weighted average grant date fair value, granted (in dollars per share)			$ 17.11
Weighted average grant date fair value, vested (in dollars per share)			$ 17.76
Weighted average grant date fair value, forfeited (in dollars per share)			$ 19.69
Weighted average grant date fair value, nonvested, end of period (in dollars per share)			$ 18.32	$ 18.72