Derivative Instruments (Cash Flow Hedges) (Details) (Interest Rate Swaps, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Derivatives In Cash Flow Hedging Relationships [Line Items]
Gains Losses Deferred In Accumulated Other Comprehensive Income Loss On Derivatives Effective Portion	$ 776	$ 1,863
Investment Related Gains Losses [Member]
Derivatives In Cash Flow Hedging Relationships [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	0	0
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	(6)	(17)
Investment Income [Member]
Derivatives In Cash Flow Hedging Relationships [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	218	305
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	$ 0	$ 0