Parent Company Only Financial Information (Tables)

12 Months Ended

Dec. 31, 2017

Condensed Financial Information Of Parent Company Only Disclosure [Abstract]

Parent Only Financial Statements

Condensed Balance Sheets	December 31,
	2017		2016
Assets:
Investment in banks	$	1,617,238	$	1,566,186
Other assets		17,349		16,756
Total Assets	$	1,634,587	$	1,582,942
Liabilities and Shareholders' Equity:
Accrued expense	$	1,030	$	878
Junior subordinated debt securities		61,856		61,856
Shareholders' equity		1,571,701		1,520,208
Total Liabilities and Shareholders' Equity	$	1,634,587	$	1,582,942

Condensed Statements of Income	Years Ended December 31,
	2017		2016		2015
Revenue:
Dividends received from banks	$	65,663	$	65,987	$	64,752
Earnings of subsidiaries over distributions		42,211		44,756		53,562
Other income		71		60		55
Total Revenue		107,945		110,803		118,369
Expense:
Other expense		2,315		2,392		2,331
Total Expense		2,315		2,392		2,331
Net Income	$	105,630	$	108,411	$	116,038

Condensed Statements of Cash Flows	Years Ended December 31,
	2017			2016			2015
Operating Activities:
Net income	$	105,630		$	108,411		$	116,038
Adjustments to reconcile net income to net cash provided    by operating activities:
Net change in investment in subsidiaries		(42,211	)		(44,756	)		(53,562	)
Other		(1,697	)		(739	)		(761	)
Net cash provided by operating activities		61,722			62,916			61,715
Investing Activities:
Payment for investments in subsidiaries		(30,755	)		—			—
Repayment for investments in subsidiaries		32,000			—			—
Net cash provided by investing activities		1,245			—			—
Financing Activities:
Cash dividends paid on common stock		(62,795	)		(62,666	)		(62,605	)
Other common stock transactions, net		—			(857	)		(211	)
Net cash used in financing activities		(62,795	)		(63,523	)		(62,816	)
Net change in cash and cash equivalents		172			(607	)		(1,101	)
Cash and cash equivalents at beginning of year		16,713			17,320			18,421
Cash and cash equivalents at end of year	$	16,885		$	16,713		$	17,320