Securities in an Unrealized Loss Position (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Securities in continuous unrealized loss position fair value	$ 2,895,204,000	$ 3,441,075,000
Securities in continuous unrealized loss position, aggregate losses accumulated In AOCI	69,142,000	117,453,000
Loans and Leases Receivable, Other, Allowance	3,000,000	2,000,000
Preferred stocks
Schedule of Available-for-sale Securities [Line Items]
Securities in unrealized loss positions	6
Securities in continuous unrealized loss position fair value	49,774,000	33,159,000
Securities in continuous unrealized loss position, aggregate losses accumulated In AOCI	4,165,000	6,319,000
Common stocks
Schedule of Available-for-sale Securities [Line Items]
Securities in unrealized loss positions	2
Securities in continuous unrealized loss position fair value	15,929,000	0
Securities in continuous unrealized loss position, aggregate losses accumulated In AOCI	$ 5,453,000	$ 0