Disclosures About Fair Value of Assets and Liabilities - Reconciliation of Beginning and Ending Balances of Recurring Fair Value Measurements using Significant Unobservable Level 3 Inputs (Details) (Fair Value, Measurements, Recurring, Available for Sale Securities, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Fair Value, Measurements, Recurring | Available for Sale Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of the period	$ 9,977	$ 18,328
Included in net income
Included in other comprehensive income	2,058	(176)
Purchases, issuances and settlements
Transfers in/(out) of Level 3
Principal payments	(541)	(474)
Ending balance	$ 11,494	$ 17,678