Financial Instruments (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	$ 23,418	$ 79,468
Total gains or (losses) (realized and unrealized)	521	673
Purchases	946	18,655
Sales	(1,218)	(66,413)
Settlements	(4,778)	(7,969)
Transfers in and/or out of Level 3		(996)
Balance at the end of the period	18,889	23,418
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date	281	2,449
Agency mortgage-backed securities
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	1,110	1,367
Total gains or (losses) (realized and unrealized)	(50)	(350)
Purchases		222
Sales	(1,060)	(1,232)
Settlements		(2)
Transfers in and/or out of Level 3		1,105
Balance at the end of the period		1,110
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		(181)
Collateralized debt obligations
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	671	647
Total gains or (losses) (realized and unrealized)	(567)	24
Purchases		61
Sales	(104)	(61)
Balance at the end of the period		671
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		28
Residential mortgage-backed securities
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	149	18,419
Total gains or (losses) (realized and unrealized)	(86)	(623)
Purchases		303
Sales	(51)	(17,329)
Settlements	(12)	(621)
Balance at the end of the period		149
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		14
Equities
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	28	112
Total gains or (losses) (realized and unrealized)	(28)	(84)
Balance at the end of the period		28
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		(85)
Commercial mortgage-backed securities
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	18	38,154
Total gains or (losses) (realized and unrealized)	(15)	(6,938)
Purchases		8,393
Sales	(3)	(37,432)
Settlements		(58)
Transfers in and/or out of Level 3		(2,101)
Balance at the end of the period		18
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		(58)
Other debt obligations
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period		192
Purchases		3,784
Sales		(3,976)
Preferred stock
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period		571
Total gains or (losses) (realized and unrealized)		870
Purchases		4,942
Sales		(6,383)
Investments
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	20,478	18,310
Total gains or (losses) (realized and unrealized)	1,267	1,235
Purchases	946	950
Settlements	(3,802)	(17)
Balance at the end of the period	18,889	20,478
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date	281	1,767
Derivatives
Changes in the company's Level 3 financial instruments
Balance at the beginning of the period	964	1,696
Total gains or (losses) (realized and unrealized)		6,539
Settlements	(964)	(7,271)
Balance at the end of the period		964
Changes in unrealized gains/(losses) on Level 3 assets still held at the reporting date		$ 964