Investments (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015 security	Mar. 31, 2014	Dec. 31, 2014
Schedule of Investments [Line Items]
Credit-related net investment impairment losses	$ 0	$ 0	$ 0
Regional community bank stocks, percent of average trading volumes (less than 0.1%)	0.20%
Number Of Pooled Trust Preferred Securities	5
Pooled trust preferred securities, book value	500,000
Pooled trust preferred securities, estimated fair value	1,700,000
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	267,000,000		273,000,000
Held-to-maturity Securities, Transferred Security, at Carrying Value		$ 83,400,000
Maximum [Member]
Schedule of Investments [Line Items]
Equity ownership positions in the community bank holding companies	4.00%