Loans and Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 15,671,735	[1],[2]	$ 13,900,025	[1],[2]	$ 12,699,776
Unamortized premiums	18,000		10,600
Interest Receivable	43,100		38,400
Residential Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	4,061,001		3,509,175	[3]	3,361,425
Consumer Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	2,702,560		2,549,401		2,536,688
Commercial Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	4,315,999		3,749,270		3,282,851
Commercial Real Estate Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	3,991,649		3,554,428		3,058,362
Finance Leases Portfolio Segment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 600,526		$ 537,751		$ 460,450

[1] Accrued interest of $43.1 million and $38.4 million at December 31, 2015 and December 31, 2014, respectively, are not included in the loan and lease balances.

[2] Loan and lease balances include net deferred fees and unamortized premiums of $18.0 million and $10.6 million at December 31, 2015 and December 31, 2014, respectively.

[3] U.S. Government guaranteed loans of approximately $2.0 million were reclassified from non-accrual to over 90 days past due and accruing reflective of a policy change effective in the first quarter of 2015.