Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Derivative assets (Effects of derivatives recorded in interest expense) (Details)

v3.8.0.1
Derivative assets (Effects of derivatives recorded in interest expense) (Details) - Interest Rate Caps And Swaps [Member] - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]      
Derivatives not designated as hedges $ (14,178) $ (1,628) $ (18,118)
Reclassification to Consolidated Income Statements:      
Reclassification of amounts previously recorded in AOCI 0 0 0
Effect from derivatives $ (14,178) $ (1,628) $ (18,118)