Note Loans (Composition of loans held-in-portfolio-covered loans and past due status) (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans covered under loss-sharing agreements with the FDIC	$ 607,170	$ 646,115
Covered loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	123,525	134,111
Current	483,645	512,004
Loans covered under loss-sharing agreements with the FDIC	607,170	646,115
Covered loans | Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	31,102	32,659
Covered loans | Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	16,202	17,037
Covered loans | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	76,221	84,415
Covered loans | Mortgages
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	120,544	131,138
Current	468,712	495,964
Loans covered under loss-sharing agreements with the FDIC	589,256	627,102
Covered loans | Mortgages | Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	30,197	31,413
Covered loans | Mortgages | Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	15,806	16,593
Covered loans | Mortgages | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	74,541	83,132
Covered loans | Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	2,981	2,973
Current	14,933	16,040
Loans covered under loss-sharing agreements with the FDIC	17,914	19,013
Covered loans | Consumer | Past Due 30 To 59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	905	1,246
Covered loans | Consumer | Past Due 60 To 89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	396	444
Covered loans | Consumer | Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due	$ 1,680	$ 1,283