Borrowings (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
FHLB-NY advances
Balance outstanding at end of year	$ 2,454,000	$ 2,897,000
FHLB Advances | FHLB-NY
FHLB-NY advances
Average balance during the year	2,512,425	2,765,985	2,063,700
Maximum balance at any month end during the year	2,881,000	3,215,000	2,487,000
Balance outstanding at end of year	$ 2,454,000	$ 2,897,000	$ 2,043,000
Weighted average interest rate during the year (as a percent)	2.00%	2.24%	3.45%
Weighted average interest rate at end of year	1.79%	2.07%	3.13%