Debt (New Zealand Corporate Credit Facility) (Narrative) (Details) $ in Thousands, NZD in Millions	9 Months Ended				12 Months Ended
	Sep. 30, 2015 NZD item		Sep. 30, 2015 USD ($) item		Dec. 31, 2014 USD ($)	[2]
New Zealand Westpac Corporate Credit Facility [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 50.0		$ 31,950	[1]	$ 21,829
Interest rate	1.75%		1.75%
Maturity date	Mar. 31, 2018	[1]	Mar. 31, 2018	[1]	Mar. 31, 2015
Number of tranches	2		2
New Zealand Corporate Credit Facility, Tranch 1 [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 35.0		$ 22,400
New Zealand Corporate Credit Facility, Tranch 2 [Member]
Debt Instrument [Line Items]
Contractual facility	NZD 15.0		$ 9,600

[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 September 30, 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.