Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 item	Mar. 31, 2014	Dec. 31, 2014
Business Segments
Number of reportable business segments	2
Number of consumer finance offices	51
Interest income	$ 75,477	$ 75,050
Interest expense	13,899	14,204
Provision for loan losses	900	7,485
Noninterest income	16,028	19,657
Noninterest expense	53,711	53,163
Income tax expense/ (benefit)	6,825	5,244
Net income	16,170	14,611
Total assets	7,890,359	7,973,313	7,775,033
All Other
Business Segments
Interest income	219	323
Interest expense	436	429
Noninterest income	29	2,336
Noninterest expense	318	380
Income tax expense/ (benefit)	(385)	405
Net income	(696)	839
Total assets	17,545	19,830
Intersegment
Business Segments
Interest income	(575)	(606)
Community Banks
Business Segments
Interest income	70,928	70,068
Interest expense	12,888	13,169
Provision for loan losses	250	6,850
Noninterest income	15,729	17,033
Noninterest expense	50,440	49,862
Income tax expense/ (benefit)	7,035	4,513
Net income	16,619	13,313
Total assets	7,769,901	7,849,806
Community Banks | Intersegment
Business Segments
Interest income	575	606
Consumer Finance
Business Segments
Interest income	4,330	4,659
Interest expense	575	606
Provision for loan losses	650	635
Noninterest income	270	288
Noninterest expense	2,953	2,921
Income tax expense/ (benefit)	175	326
Net income	247	459
Total assets	$ 102,913	$ 103,677