Condensed Parent Company Only Financial Statements (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 66,593	$ 53,091	$ 67,209
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of premiums and deferred costs	15,794	16,762	8,288
Net cash provided by operating activities	232,664	187,413	227,693
Cash flows from investing activities:
Redemption of Astoria Capital Trust I common securities	3,866
Net cash provided by investing activities	488,662	377,632	935,612
Cash flows from financing activities:
Proceeds from borrowings with original terms greater than three months		950,000	200,000
Repayments of borrowings with original terms greater than three months	(553,866)	(1,144,000)	(1,116,000)
Cash payments for debt issuance costs		(2,653)
Proceeds from issuance of preferred stock	135,000
Cash payments for preferred stock issuance costs	(5,204)
Cash dividends paid to stockholders	(20,688)	(24,104)	(49,435)
Net tax benefit shortfall from stock-based compensation	(800)	(4,123)	(263)
Net cash used in financing activities	(720,849)	(576,276)	(1,149,617)
Net increase (decrease) in cash and cash equivalents	477	(11,231)	13,688
Cash and cash equivalents at beginning of year	121,473	132,704	119,016
Cash and cash equivalents at end of year	121,950	121,473	132,704
Supplemental disclosure:
Interest paid	180,871	258,503	322,225
Astoria Financial Corporation
Cash flows from operating activities:
Net income	66,593	53,091	67,209
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed earnings of subsidiaries	(39,528)	(35,015)	(23,626)
Amortization of premiums and deferred costs	531	837	699
(Increase) decrease in other assets, net of other liabilities and amounts due to subsidiaries	(998)	846	(1,423)
Net cash provided by operating activities	26,598	19,759	42,859
Cash flows from investing activities:
Principal payments on ESOP loans receivable	5,908	6,235	7,780
Redemption of Astoria Capital Trust I common securities	3,866
Net cash provided by investing activities	9,774	6,235	7,780
Cash flows from financing activities:
Proceeds from borrowings with original terms greater than three months		250,000
Repayments of borrowings with original terms greater than three months	(128,866)	(250,000)
Cash payments for debt issuance costs		(2,653)
Proceeds from issuance of preferred stock	135,000
Cash payments for preferred stock issuance costs	(5,204)
Cash dividends paid to stockholders	(20,688)	(24,104)	(49,435)
Net tax benefit shortfall from stock-based compensation	(800)	(4,123)	(263)
Net cash used in financing activities	(20,558)	(30,880)	(49,698)
Net increase (decrease) in cash and cash equivalents	15,814	(4,886)	941
Cash and cash equivalents at beginning of year	47,604	52,490	51,549
Cash and cash equivalents at end of year	63,418	47,604	52,490
Supplemental disclosure:
Interest paid	$ 18,898	$ 31,535	$ 26,563