Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Loans receivable, allowance for loan losses	$ 24,691	$ 24,691	$ 22,359
Preferred stock, par value per share	$ 0.01	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Preferred stock, shares issued	8,340	8,340	7,807
Preferred stock, shares outstanding	8,340	8,340	7,807
Common stock, no par value	$ 0	$ 0	$ 0
Common stock, shares authorized	40,000,000	40,000,000	40,000,000
Common stock, shares issued	18,444,453	18,444,453	18,352,748
Common stock, shares outstanding	16,477,235	16,477,235	15,889,306
Treasury stock, shares	1,967,218	1,967,218	2,463,442
Series C Preferred Stock [Member]
Preferred stock, dividend rate	6.00%	6.00%	6.00%
Series D Preferred Stock [Member]
Preferred stock, dividend rate	4.50%	4.50%	4.50%
Preferred stock, liquidation preference per share			$ 10,000
Series G Preferred Stock [Member]
Preferred stock, dividend rate	6.00%	6.00%
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000
Series F Preferred Stock [Member]
Preferred stock, shares outstanding	6,465	6,465
Preferred stock, dividend rate	6.00%	6.00%	6.00%
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000	$ 1,000