Debt (New Zealand Corporate Credit Facility) (Narrative) (Details) $ in Thousands, NZD in Millions	12 Months Ended
	Dec. 31, 2015 NZD item		Dec. 31, 2015 USD ($) item		Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Line of credit facility, term	3 years		3 years
Contractual facility | $			$ 207,075		$ 201,318
New Zealand Westpac Corporate Credit Facility [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 50.0		$ 34,210	[1]	$ 21,829	[2]
Interest rate	1.75%		1.75%
Maturity date	Mar. 31, 2018	[1]	Mar. 31, 2018	[1]	Mar. 31, 2015	[2]
Number of tranches | item	2		2
New Zealand Corporate Credit Facility, Tranch 1 [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 35.0		$ 23,900
New Zealand Corporate Credit Facility, Tranch 2 [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 15.0		$ 10,300

[1] The contractual facilities and outstanding balances of the FC-denominated borrowings were translated into U.S. dollars based on the applicable exchange rates as of December 31, 2015.

[2] The contractual facilities and outstanding balances of the FC-denominated borrowings were translated into U.S. dollar based on the applicable exchange rates as of December 31, 2014.