Insurance Recoveries (Narrative) (Details) NZD in Thousands, $ in Thousands	1 Months Ended			6 Months Ended		12 Months Ended
	May 31, 2017 USD ($)	Apr. 30, 2017 NZD	Apr. 30, 2017 USD ($)	Jun. 30, 2017 NZD	Jun. 30, 2017 USD ($)	Dec. 31, 2016 NZD	Dec. 31, 2016 USD ($)
Insurance Recoveries [Abstract]
Insurance coverage limit		NZD 36,000	$ 25,000
Proceeds from insurance settlement	$ 20,000	NZD 28,900				NZD 7,100	$ 5,000
Total insurance gains				NZD 14,849	$ 10,741