Loans Receivable and Allowance for Loan Losses - Schedule of Summarized Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans	$ 5,196,663	$ 4,904,617
Premiums on purchased loans	4,202	4,964
Unearned discounts	(62)	(78)
Net deferred fees	(5,990)	(4,804)
Loans receivable	5,194,813	4,904,699
Mortgage Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	3,686,862	3,459,056
Residential [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	1,174,043	1,265,015
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	1,400,624	1,349,950
Multi-Family [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	928,906	723,958
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total mortgage loans	183,289	120,133
Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans	932,199	866,395
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total gross loans	$ 577,602	$ 579,166