The Company and Summary of Significant Accounting Policies - Additional Information (Detail) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($) Categories shares	Sep. 30, 2015 shares
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]
Number of business channels | Categories	2
Number of revenue and cost categories | Categories	2
Unvested service-based restricted stock awards included in the calculation of earnings per share | shares	0.6	0.7
Deposits Assets
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]
Cash subject to FDIC insurance | $	$ 8.4
Cash not subject to FDIC insurance | $	$ 143.0