Leases (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Leases [Line Items]
Operating Days	24379 days
One Year From Balance Sheet [Member]
Leases [Line Items]
Operating Days	1196 days
More Than One and Within Two Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4745 days
More Than Two and Within Three Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4758 days
More Than Three and Within Four Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4713 days
More Than Four and Within Five Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	3929 days
More Than Five Years From Balance Sheet and Thereafter [Member]
Leases [Line Items]
Operating Days	5038 days
Bareboat Charters In [Member]
Leases [Line Items]
2014	$ 25,144
2015	97,816
2016	99,038
2017	98,219
2018	93,200
Thereafter	151,098
Net minimum lease payments	564,515
Operating Days	24379 days
Bareboat Charters In [Member] | One Year From Balance Sheet [Member]
Leases [Line Items]
Operating Days	1196 days
Bareboat Charters In [Member] | More Than One and Within Two Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4745 days
Bareboat Charters In [Member] | More Than Two and Within Three Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4758 days
Bareboat Charters In [Member] | More Than Three and Within Four Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	4713 days
Bareboat Charters In [Member] | More Than Four and Within Five Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	3929 days
Bareboat Charters In [Member] | More Than Five Years From Balance Sheet and Thereafter [Member]
Leases [Line Items]
Operating Days	5038 days
Time Charters In [Member]
Leases [Line Items]
2014	8,072
2015	24,167
2016	1,004
Net minimum lease payments	$ 33,243
Operating Days	3003 days
Time Charters In [Member] | One Year From Balance Sheet [Member]
Leases [Line Items]
Operating Days	794 days
Time Charters In [Member] | More Than One and Within Two Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	2136 days
Time Charters In [Member] | More Than Two and Within Three Years From Balance Sheet [Member]
Leases [Line Items]
Operating Days	73 days