Legal Matters (Details) (USD $)			0 Months Ended
	Jul. 16, 2013 First Manhattan	Nov. 30, 2010 Federal securities class action lawsuit person	Jul. 12, 2013 Shareholder derivative lawsuit	Jul. 18, 2013 Proxy Related Lawsuits First Manhattan
Securities Related Class Action Lawsuits
Loss contingency, number of officers, defendants in lawsuit		2
Amount of damages sought			$ 0
Outstanding shares of common stock owned (as a percent)	9.90%
Reimbursement of expenses incurred in connection with proxy solicitation				$ 2,900,000