Forward Equity	9 Months Ended
Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Forward Equity Sales	Forward Equity Under a forward equity agreement, the Company may sell shares of common stock up to an aggregate notional amount of $400.0 million. During 2012, the Company entered into contracts to sell a notional amount of $147.2 million at an average share price of $121.37. During 2013, the Company net settled $77.0 million notional amount of forward equity contracts at an average share price of $185.56. During the first half of 2014, the Company net settled $70.2 million notional amount of forward equity contracts at an average share price of $198.71. The Company has $252.8 million remaining notional amount that it may elect to sell under the forward equity agreement.

Forward Equity

Under a forward equity agreement, the Company may sell shares of common stock up to an aggregate notional amount of $400.0 million. During 2012, the Company entered into contracts to sell a notional amount of $147.2 million at an average share price of $121.37. During 2013, the Company net settled $77.0 million notional amount of forward equity contracts at an average share price of $185.56. During the first half of 2014, the Company net settled $70.2 million notional amount of forward equity contracts at an average share price of $198.71. The Company has $252.8 million remaining notional amount that it may elect to sell under the forward equity agreement.