Commitments and Contingencies (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Purchase commitments entered in October 2011
Future commitments
Advance Deposits	$ 50,000
Total Minimum Commitment	286,000
Remaining Deposit	38,273
Remaining Commitments, Net of Deposit	13,034
Purchase commitments entered in October 2012
Future commitments
Advance Deposits	0
Total Minimum Commitment	83,000
Remaining Deposit	0
Remaining Commitments, Net of Deposit	3,265
Purchase commitments entered in April 2013
Future commitments
Advance Deposits	28,931
Total Minimum Commitment	42,800
Remaining Deposit	28,931
Remaining Commitments, Net of Deposit	13,869
Purchase commitments entered in September 2013
Future commitments
Advance Deposits	0
Total Minimum Commitment	50,730
Remaining Deposit	0
Remaining Commitments, Net of Deposit	$ 39,958