Condensed Parent Company Only Financial Statements - Condensed Statements of Financial Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
ASSETS:
Cash	$ 200,538	$ 143,185
Other assets	166,535	173,138
Total assets	15,076,211	15,640,021
Liabilities and stockholders’ equity:
Other liabilities	227,079	251,951
Stockholders’ equity	1,663,448	1,580,070	$ 1,519,513	$ 1,293,989
Total liabilities and stockholders’ equity	15,076,211	15,640,021
Astoria Financial Corporation
ASSETS:
Cash	102,338	75,199
Other assets	760	711
Total assets	1,916,443	1,832,122
Liabilities and stockholders’ equity:
Other borrowings, net	249,222	248,691
Other liabilities	3,773	3,361
Stockholders’ equity	1,663,448	1,580,070
Total liabilities and stockholders’ equity	1,916,443	1,832,122
Astoria Financial Corporation | Astoria Bank
ASSETS:
Investment in subsidiary	1,812,393	1,755,078
Astoria Financial Corporation | AF Insurance Agency, Inc
ASSETS:
Investment in subsidiary	$ 952	$ 1,134