Investments (Continuous unrealized loss position) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Available-for-sale And Held-To-Maturity Securities, Continuous Unrealized Loss Position [Abstract] [Abstract]
Less than 12 months, fair value	$ 69,199	$ 41,564
Less than 12 months, unrealized losses	(943)	(441)
12 months or longer, fair value	11,408	3,993
12 months or longer, unrealized losses	(582)	(483)
Total, fair value	80,607	45,557
Total, unrealized losses	(1,525)	(924)
Residential MBS
Available-for-sale And Held-To-Maturity Securities, Continuous Unrealized Loss Position [Abstract] [Abstract]
Less than 12 months, fair value	57,180	39,905
Less than 12 months, unrealized losses	(785)	(433)
12 months or longer, fair value	11,408	3,993
12 months or longer, unrealized losses	(582)	(483)
Total, fair value	68,588	43,898
Total, unrealized losses	(1,367)	(916)
State and municipal securities
Available-for-sale And Held-To-Maturity Securities, Continuous Unrealized Loss Position [Abstract] [Abstract]
Less than 12 months, fair value	12,019	1,659
Less than 12 months, unrealized losses	(158)	(8)
12 months or longer, fair value	0	0
12 months or longer, unrealized losses	0	0
Total, fair value	12,019	1,659
Total, unrealized losses	$ (158)	$ (8)