Summary of Significant Accounting Policies - Recertification Costs and Deferred Dry Dock Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Deferred dry dock expenses, net	$ 19,615	$ 11,631
Accumulated amortization deferred dry dock	18,300	7,500
Dry dock amortization expense	$ 10,800	$ 14,100	$ 14,800
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Dry dock amortization period	30 months
Dry dock recertification process period	1 month
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Dry dock amortization period	60 months
Dry dock recertification process period	2 months