Parent Company Financial Statements (Statement of Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income:
Total income	$ 153,865	$ 155,910	$ 137,719
Expenses:
Interest on junior subordinated debentures	1,484	1,570	1,568
Legal and professional fees	2,330	2,240	1,927
Income before income taxes	52,680	50,872	42,646
Income tax benefit	(16,527)	(15,798)	(12,922)
Net income	36,153	35,074	29,724
Parent Company [Member]
Income:
Dividends from subsidiaries	24,481	16,188	14,439
Other income	20	3	2
Total income	24,501	16,191	14,441
Expenses:
Interest on junior subordinated debentures	1,484	1,570	1,568
Legal and professional fees	145	127	118
Other	279	279	257
Total expenses	1,908	1,976	1,943
Income before income taxes	22,593	14,215	12,498
Income tax benefit	661	682	669
Income before equity in undistributed earnings of subsidiaries	23,254	14,897	13,167
Equity in undistributed earnings of subsidiaries	12,899	20,177	16,557
Net income	$ 36,153	$ 35,074	$ 29,724