Basis Of Presentation And Accounting Policies (Carrying Amount and Estimated Fair Value of Company's Financial Instruments) (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Financial assets:
Loans, net	$ 1,989,786
Financial liabilities:
Deposits	2,581,465
Carrying Amount [Member]
Financial assets:
Loans, net	1,960,195	1,868,419	1,929,085
Financial liabilities:
Deposits	2,580,117	2,591,566	2,628,892
Other borrowings		20,000	21,000
Level 1 [Member]
Financial assets:
Loans, net
Financial liabilities:
Deposits
Other borrowings
Level 2 [Member]
Financial assets:
Loans, net	1,989,786
Financial liabilities:
Deposits	2,581,465
Level 3 [Member]
Financial assets:
Loans, net
Financial liabilities:
Deposits
Other borrowings
Fair Value [Member]
Financial assets:
Loans, net		1,877,320	1,907,017
Financial liabilities:
Deposits		2,593,113	2,629,974
Other borrowings		$ 20,936	$ 20,814