Related-Party Transactions (Details) (Zions Bancorporation, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 item	Dec. 31, 2012 item
Related Party Transactions
Cash balance with related party	$ 81.8	$ 56.4
Minimum
Related Party Transactions
Refinancing term		3 years
Maximum
Related Party Transactions
Refinancing term		4 years
CRJ 200
Related Party Transactions
Equity participation in leveraged leases on number of aircraft	3
Number of refinanced aircraft		6
CRJ700
Related Party Transactions
Equity participation in leveraged leases on number of aircraft	2
Number of refinanced aircraft		2
Brasilia turboprop aircraft
Related Party Transactions
Equity participation in leveraged leases on number of aircraft	5