Related-Party Transactions (Details) (Zions Bancorporation, USD $) In Millions, unless otherwise specified			12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Minimum	Dec. 31, 2012 Maximum	Dec. 31, 2012 CRJ 200 item	Dec. 31, 2012 CRJ 700s item	Dec. 31, 2012 Brasilia turboprop aircraft item
Related Party Transactions
Equity participation in leveraged leases on number of aircraft					3	2	5
Number of refinanced aircraft					6	2
Refinancing term			3 years	4 years
Cash balance with related party	$ 56.4	$ 51.8