Loans Receivable and Allowance for Loan Losses - Summary of Recorded Investment Net Charge-Offs, Unpaid Principal Balance and Related Allowance for Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, Total	$ 57,916		$ 57,916		$ 44,608
Unpaid Principal Balance
Unpaid Principal Balance, Total	59,993		59,993		45,929
Related Allowance	3,666		3,666		2,273
Average Recorded Investment
Average Recorded Investment, Total	57,000	$ 41,608	52,868	$ 42,782
Interest Income Recognized
Interest Income Recognized, Total	634	1,117	1,141	1,522
Multi-family
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	0		0		661
Recorded Investment Net of Charge Offs, With an allowance recorded	386		386
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	0		0		661
Unpaid Principal Balance, With an allowance recorded	386		386
Related Allowance	202		202
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	0	0	220	0
Average Recorded Investment, With an allowance recorded	390		260
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	0	0	0	0
Interest Income Recognized, With an allowance recorded	5		10
Commercial and industrial
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	20,833		20,833		12,056
Recorded Investment Net of Charge Offs, With an allowance recorded	7,731		7,731		5,565
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	22,911		22,911		13,028
Unpaid Principal Balance, With an allowance recorded	7,731		7,731		5,914
Related Allowance	3,183		3,183		1,990
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	19,892	7,122	17,280	9,356
Average Recorded Investment, With an allowance recorded	8,034	10,686	7,211	7,735
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	286	439	473	604
Interest Income Recognized, With an allowance recorded	41	96	112	101
Commercial real estate - owner occupied
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	9,840		9,840		8,317
Recorded Investment Net of Charge Offs, With an allowance recorded	0		0		12
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	9,840		9,840		8,317
Unpaid Principal Balance, With an allowance recorded	0		0		12
Related Allowance	0		0		1
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	9,882	5,175	9,360	6,177
Average Recorded Investment, With an allowance recorded	6	18	8	20
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	108	122	202	185
Interest Income Recognized, With an allowance recorded	0	0	0	0
Commercial real estate - non-owner occupied
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	5,427		5,427		4,276
Recorded Investment Net of Charge Offs, With an allowance recorded	535		535		555
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	5,426		5,426		4,276
Unpaid Principal Balance, With an allowance recorded	535		535		555
Related Allowance	177		177		148
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	4,755	6,805	4,595	8,135
Average Recorded Investment, With an allowance recorded	538	1,072	544	1,177
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	0	246	15	374
Interest Income Recognized, With an allowance recorded	2	7	4	7
Construction
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded					0
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded					0
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded		1,497		1,773
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded		0		0
Other
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	44		44		48
Recorded Investment Net of Charge Offs, With an allowance recorded	0		0		92
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	44		44		48
Unpaid Principal Balance, With an allowance recorded	0		0		92
Related Allowance	0		0		50
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	45	35	46	30
Average Recorded Investment, With an allowance recorded	27	73	48	87
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	0	0	0	0
Interest Income Recognized, With an allowance recorded	0	0	0	0
Residential real estate
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	3,871		3,871		4,331
Recorded Investment Net of Charge Offs, With an allowance recorded	399		399		395
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	3,871		3,871		4,331
Unpaid Principal Balance, With an allowance recorded	399		399		395
Related Allowance	104		104		84
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	4,013	3,924	4,119	3,841
Average Recorded Investment, With an allowance recorded	544	454	494	424
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	20	21	44	42
Interest Income Recognized, With an allowance recorded	0	0	0	0
Manufactured housing
Recorded Investment Net of Charge offs
Recorded Investment Net of Charge Offs, With no related allowance recorded	8,850		8,850		8,300
Unpaid Principal Balance
Unpaid Principal Balance, With no related allowance recorded	8,850		8,850		$ 8,300
Average Recorded Investment
Average Recorded Investment, With no related allowance recorded	8,874	4,747	8,683	4,027
Interest Income Recognized
Interest Income Recognized, With no related allowance recorded	$ 172	$ 186	$ 281	$ 209