Loans - Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	$ 123,376	$ 185,281	$ 238,175
Income Recognized	1,692	1,631	1,659
Impaired Financing Receivable, Average Recorded Investment and Cash Basis Method Interest Income
Interest income on impaired loans if interest had been accrued	5,786	8,463	12,358
Commercial real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	66,330	78,670	85,702
Income Recognized	1,092	1,339	633
Land acquisition & development construction real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	19,523	44,457	57,675
Income Recognized	487	110	96
Residential construction real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	1,893	8,431	19,769
Income Recognized	0	4	384
Commercial construction real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	3,936	16,401	20,676
Income Recognized	4	0	0
Total construction loans
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	25,352	69,289	98,120
Income Recognized	491	114	480
Residential real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	8,104	13,703	15,768
Income Recognized	17	26	258
Agricultural real estate
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	8,230	6,936	6,188
Income Recognized	8	41	167
Total real estate loans
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	108,016	168,598	205,778
Income Recognized	1,608	1,520	1,538
Commercial
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	15,047	15,741	31,490
Income Recognized	68	84	121
Agricultural
Schedule of Average Recorded Investment in and Income Recognized on Impaired Loans
Average Recorded Investment	313	942	907
Income Recognized	$ 16	$ 27	$ 0