Borrowings (Details 6) (USD $)						12 Months Ended				0 Months Ended		0 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 1999 Astoria Capital Trust I	Dec. 31, 2012 Reverse repurchase agreements	Dec. 31, 2011 Reverse repurchase agreements	Dec. 31, 2012 Reverse repurchase agreements Minimum	Dec. 31, 2011 Reverse repurchase agreements Minimum	Dec. 31, 2012 Reverse repurchase agreements Maximum	Dec. 31, 2011 Reverse repurchase agreements Maximum	Sep. 13, 2012 5.75% Senior Unsecured Notes due 2012	Dec. 31, 2011 5.75% Senior Unsecured Notes due 2012	Jun. 19, 2012 5.00% Senior Unsecured Notes due 2017	Dec. 31, 2012 5.00% Senior Unsecured Notes due 2017	Dec. 31, 2012 Junior Subordinated Debt	Dec. 31, 2011 Junior Subordinated Debt
Borrowings
Debt instrument, contractual maturities						5 years	5 years	10 years	10 years
Securities pledged as collateral for repurchase agreements, Amortized Cost				$ 1,210,000,000	$ 1,870,000,000
Securities pledged as collateral for repurchase agreements, Fair Value				1,230,000,000	1,910,000,000
Amount of debt sold												250,000,000
Debt instrument, percentage rate (as a percent)			9.75%							5.75%		5.00%	5.00%	9.75%	9.75%
Minimum notice requirement													30 days
Amount of debt redeemed										250,000,000
Prepayment penalty										1,200,000
Capital Securities			125,000,000
Other borrowings, net	376,496,000	378,573,000									249,700,000		247,600,000	128,900,000	128,900,000
Common stock			$ 3,900,000