Shareholders' Equity (Details) (USD $)	3 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012
Shareholders' Equity
Current quarter dividend paid in next quarter (in dollars per share)	$ 0.25			$ 0.12
Declared and paid cash dividend on common stock (in dollars per share)		$ 0.12	$ 0.12		$ 0.10	$ 0.10
Prior quarter dividend paid (in dollars per share)						$ 0.10