Long-term Funding, Composition (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Long-term Funding
FHLB advances	$ 2,265,188	$ 1,750,225
Senior notes, at par	250,000	680,000
Subordinated notes, at par	250,000	250,000
Other Long-term Debt and Capitalized Costs	(3,393)	(4,061)
Total long-term funding	$ 2,761,795	$ 2,676,164