Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounts receivable, non-trade	$ 49,707us-gaap_NontradeReceivablesCurrent	$ 109,114us-gaap_NontradeReceivablesCurrent
Accounts receivable, related party balance	38,616	16,371
Accumulated depreciation on vessels and equipment	2,627,499	2,135,780
Accumulated amortization on vessels under capital lease	50,898	152,020
Amounts due to joint venture partners	$ 0us-gaap_DueToRelatedPartiesNoncurrent	$ 13,282us-gaap_DueToRelatedPartiesNoncurrent
Common stock, par value	$ 0.001	$ 0.001
Common stock, share authorized	725,000,000us-gaap_CommonStockSharesAuthorized	725,000,000us-gaap_CommonStockSharesAuthorized
Common stock, share issued	73,299,702us-gaap_CommonStockSharesIssued	71,528,599us-gaap_CommonStockSharesIssued
Common stock, share outstanding	72,500,502us-gaap_CommonStockSharesOutstanding	70,729,399us-gaap_CommonStockSharesOutstanding
Minimum [Member]
Range of interest	0.00%	0.00%
Maximum [Member]
Range of interest	8.00%	8.00%

Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer.

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