Leases (Details 1) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Credit risk profile by creditworthiness category of direct financing lease receivables
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	$ 478,735	$ 449,310
Very low risk to low risk
Credit risk profile by creditworthiness category of direct financing lease receivables
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	203,388	198,496
Moderate
Credit risk profile by creditworthiness category of direct financing lease receivables
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	197,484	158,790
Moderately high to high risk
Credit risk profile by creditworthiness category of direct financing lease receivables
Credit risk profile by creditworthiness category of direct financing lease receivables, Total	$ 77,863	$ 92,024