Income Taxes (Tables)

9 Months Ended

Sep. 30, 2013

Income Tax Disclosure [Abstract]

Summary of Differences in Taxes Computed at Statutory Rate

Following is a summary of the major items comprising the differences in taxes from continuing operations computed at the federal statutory rate and as recorded in the consolidated statement of income for the three and nine months ended September 30:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(dollars in thousands)	2013			2012			2013			2012
Provision at statutory rate of 35%	$	10,786		$	8,960		$	37,578		$	32,815
Tax-exempt income		(3,533	)		(2,732	)		(9,522	)		(7,878	)
Reversal of portion of unrecognized tax benefits		(381	)		(292	)		(381	)		(292	)
State income taxes		386			249			2,757			2,276
State statutory rate change		—			—			1,257			—
Interim period effective rate adjustment		(268	)		(87	)		(490	)		(793	)
Other, net		(121	)		(237	)		(204	)		(1,038	)
Income tax expense	$	6,869		$	5,861		$	30,995		$	25,090
Effective tax rate		22.3	%		22.9	%		28.9	%		26.8	%

Summary of Reconciliation of Unrecognized Tax Benefits

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

(dollars in thousands)	2013			2012
Balance at January 1	$	3,953		$	4,145
Additions (reductions) based on tax positions related to the current year		21			1
Reductions due to statute of limitations expiring		(140	)		(194	)
Balance at September 30	$	3,834		$	3,952