Subsequent Events (Details) (USD $)		1 Months Ended	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Feb. 14, 2014 Subsequent Event	Dec. 31, 2013 Convertible Notes	Feb. 14, 2014 Convertible Notes Subsequent Event	Dec. 31, 2013 Call Options	Feb. 14, 2014 Call Options Subsequent Event	Dec. 31, 2013 Warrants	Dec. 31, 2012 Warrants	Feb. 14, 2014 Warrants Subsequent Event
Subsequent Events (Textuals) [Abstract]
Cash dividend declared per common share		$ 0.35
Dividends		$ 6,400,000
Conversion rate of common stock shares per $1,000 of principal amount			20.7903	20.8234
Principal amount in conversion feature			$ 1,000	$ 1,000
Conversion price of note	$ 48.10	$ 48.02
Exercise price of call options					$ 48.10	$ 48.02
Exercise price per share of Warrants							61.08	61.31	60.98