Fair Value Measurement (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Minimum [Member] broker	Dec. 31, 2013 Commercial Mortgage Backed Securities [Member] Level 2 [Member]	Dec. 31, 2012 Commercial Mortgage Backed Securities [Member] Level 2 [Member]
Fair Value Measurement [Line Items]
Percentage of portfolio of unadjusted fair values obtained	100.00%
Percentage of portfolio of specific unadjusted broker quotes obtained	0.50%
Number of knowledgeable outside security brokers consulted to determine fair value		1
Trading securities, fair value disclosure			$ 21.9	$ 4.3