Shareholders' Equity (Details) (USD $)	3 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2014 Subsequent event
Subsequent Event [Line Items]
Prior quarter dividend paid (in dollars per share)	$ 0.25			$ 0.12	$ 0.12			$ 0.10		$ 0.25
Common stock dividends declared (in dollars per share)	$ 0.25	$ 0.25	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.1	$ 0.1	$ 0.10
Current quarter dividend declared and paid (in dollars per share)			$ 0.12	$ 0.12			$ 0.10	$ 0.10