Shareholders' Equity (Details 2) (USD $)			0 Months Ended
	Dec. 31, 2013 registration_statement	Dec. 31, 2012	Sep. 21, 1998 Preferred stock purchase right	May 02, 2008 Amended Rights Agreement	May 02, 2008 Amended Rights Agreement Series A Junior Participating Preferred Stock
Shelf Registration Statements on Form S-4
Number of effective registration statements	2
Remaining shares available for issuance under registration statement	13,469,000
Stock Purchase Rights
Preferred stock purchase right issued as dividend			1
Number of rights held by the shareholders for each share of common stock				1
Minimum percentage of beneficial ownership interest in the entity's common stock to be acquired by a party for the Rights to be exercisable				15.00%
Fraction of a share of Series A Junior Participating Preferred Stock that could be purchased for each Right					$ 0.001
Par value (in dollars per share)	$ 0.01	$ 0.01			$ 0.01
Purchase price per one one-thousandth of a share of Series A Junior Participating Preferred Stock (in dollars per share)					$ 37
Minimum percentage of consolidated assets, cash flow or earning power to be sold for the Rights to be exercisable				50.00%
Redemption price (in dollars per share)					$ 0.001