Stockholders' Equity (Details) (USD $)	0 Months Ended			9 Months Ended
	Nov. 29, 2013	May 30, 2013	Feb. 21, 2012	Sep. 30, 2013	Sep. 30, 2012
Class of Stock [Line Items]
Gross proceeds from the issuance of common stock			$ 225,000,000
Stock issued during period			6,122,000
Sale of stock, price per share			$ 36.75
Proceeds from sale of common stock, net of issuance costs				0	218,983,000
Dividends declared, per share				$ 0.50
Dividends paid, per share		$ 0.125
Dividends paid				$ 12,392,000	$ 0
Dividends, payment date	Nov. 29, 2013
Dividends, record date	Nov. 01, 2013