Equity (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stockholders' Equity Note [Abstract]
Number of operating partnership units converted to shares of common stock			2,200,000	1,400,000
Number of operating partnership units redeemed for cash			120,000	13,000
Total purchase price			$ 2,827	$ 352
Average redemption price (usd per share)			$ 23.56	$ 26.68
Common stock options settled			691,000
Purchase price of stock options			4,524	0
Average purchase price of options (usd per share)			$ 6.55
Noncontrolling interest, ownership percentage by noncontrolling owners	16.00%		16.00%
Number of shares of common stock issued upon redemption of one OP unit			1
Non-cash amortization of equity compensation	1,348	1,528	4,049	4,560
Capitalized equity compensation	$ 97	$ 97	$ 367	$ 304