Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended			0 Months Ended
	Mar. 31, 2014 security	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Minimum [Member]	Mar. 31, 2014 Maximum [Member]	Apr. 02, 2014 Subsequent Event [Member]
Schedule of Investments [Line Items]
Equity ownership positions in the community bank holding companies				2.00%	5.00%
Credit-related net investment impairment losses	$ 0	$ 0	$ 0
Regional community bank stocks, percent of average trading volumes (less than 0.1%)		0.10%
Number Of Pooled Trust Preferred Securities	5
Pooled trust preferred securities, book value	3.0
Pooled trust preferred securities, estimated fair value	1.6
Annual prepayment rate	1.00%		1.00%
Annual prepayments maturity	100.00%		100.00%
Additional basis points	1.50%		1.50%
Carrying value of securities pledged	270		278
Held-to-maturity Securities, Transferred Security, at Carrying Value						83.4
Held-to-maturity Securities, Transferred Security, Unrealized Gain (Loss)	$ 0.1					$ 0.1