Allowances for Loan Losses - Additional Information about Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	$ 73,636	$ 116,385
Impaired loans with no related allowance, Unpaid Principal Balance	88,937	160,938
Impaired loans with no related allowance, Average Recorded Investment	95,557	171,550
Impaired loans with no related allowance, Interest Income Recognized	2,445	4,050
Impaired loans with an allowance recorded, Related Allowance	0	0
Impaired loans with an allowance recorded, Average Recorded Investment	690	3,342
Total impaired loans, Recorded Investment	73,636	116,385
Total impaired loans, Unpaid Principal Balance	88,937	160,938
Total impaired loans, Average Recorded Investment	96,247	174,892
Total impaired loans, Interest Income Recognized	2,445	4,050
Multi-Family
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	36,148	78,771
Impaired loans with no related allowance, Unpaid Principal Balance	43,459	94,265
Impaired loans with no related allowance, Average Recorded Investment	56,218	117,208
Impaired loans with no related allowance, Interest Income Recognized	916	1,991
Impaired loans with an allowance recorded, Related Allowance	0	0
Impaired loans with an allowance recorded, Average Recorded Investment		2,442
Total impaired loans, Recorded Investment	36,148	78,771
Total impaired loans, Unpaid Principal Balance	43,459	94,265
Total impaired loans, Average Recorded Investment	56,218	119,650
Total impaired loans, Interest Income Recognized	916	1,991
Commercial Real Estate
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	28,558	30,619
Impaired loans with no related allowance, Unpaid Principal Balance	30,907	32,474
Impaired loans with no related allowance, Average Recorded Investment	29,827	43,566
Impaired loans with no related allowance, Interest Income Recognized	1,136	1,604
Impaired loans with an allowance recorded, Related Allowance	0	0
Impaired loans with an allowance recorded, Average Recorded Investment	613	900
Total impaired loans, Recorded Investment	28,558	30,619
Total impaired loans, Unpaid Principal Balance	30,907	32,474
Total impaired loans, Average Recorded Investment	30,440	44,466
Total impaired loans, Interest Income Recognized	1,136	1,604
One-to-four family
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	1,282
Impaired loans with no related allowance, Unpaid Principal Balance	1,281
Impaired loans with no related allowance, Average Recorded Investment	1,061	3,611
Impaired loans with no related allowance, Interest Income Recognized		89
Impaired loans with an allowance recorded, Related Allowance	0	0
Impaired loans with an allowance recorded, Average Recorded Investment	77
Total impaired loans, Recorded Investment	1,282
Total impaired loans, Unpaid Principal Balance	1,281
Total impaired loans, Average Recorded Investment	1,138	3,611
Total impaired loans, Interest Income Recognized		89
Acquisition, Development and Construction
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	935
Impaired loans with no related allowance, Unpaid Principal Balance	1,245
Impaired loans with no related allowance, Average Recorded Investment	467	275
Impaired loans with no related allowance, Interest Income Recognized	158
Impaired loans with an allowance recorded, Related Allowance	0	0
Total impaired loans, Recorded Investment	935
Total impaired loans, Unpaid Principal Balance	1,245
Total impaired loans, Average Recorded Investment	467	275
Total impaired loans, Interest Income Recognized	158
Total Commercial and Industrial Loans
Financing Receivable, Impaired [Line Items]
Impaired loans with no related allowance, Recorded Investment	6,713	6,995
Impaired loans with no related allowance, Unpaid Principal Balance	12,045	34,199
Impaired loans with no related allowance, Average Recorded Investment	7,984	6,890
Impaired loans with no related allowance, Interest Income Recognized	235	366
Impaired loans with an allowance recorded, Related Allowance	0	0
Total impaired loans, Recorded Investment	6,713	6,995
Total impaired loans, Unpaid Principal Balance	12,045	34,199
Total impaired loans, Average Recorded Investment	7,984	6,890
Total impaired loans, Interest Income Recognized	$ 235	$ 366