Debt - Senior Secured Facilities Agreement (Narrative) (Details)	Dec. 31, 2015 USD ($) tranche
Debt Instrument [Line Items]
Number of tranches | tranche	2
Tranche A, Revolving Cash Advance Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 161,000,000
Tranche B, Working Capital Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	27,000,000
New Zealand JV | Senior Secured Facilities Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	188,000,000
New Zealand JV | Tranche B, Working Capital Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 27,000,000