Investments (Narrative) (Details)	6 Months Ended		12 Months Ended
	Jun. 30, 2015 USD ($) security	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
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%)	0.70%
Number Of Pooled Trust Preferred Securities | security	5
Pooled trust preferred securities, book value	$ 1,000,000
Pooled trust preferred securities, estimated fair value	$ 1,900,000
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	$ 262,000,000		$ 273,000,000
Held-to-maturity Securities, Transferred Security, at Carrying Value	$ 0	$ 83,400,000
Maximum [Member]
Schedule of Investments [Line Items]
Equity ownership positions in the community bank holding companies	4.00%