Contingencies and Guarantees (Schedule of Changes in Repurchase Reserve) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 2,725	$ 7,250
Net increase/(decrease) to reserve	(53)	(402)
Net realized (losses)/gains	(47)	(198)
Balance at end of period	2,625	6,650
Residential Mortgages
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	2,700
Balance at end of period	$ 2,600	$ 6,700