CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
CONDENSED CONSOLIDATED BALANCE SHEETS
Vessels, accumulated depreciation (in dollars)	$ 180,865	$ 147,129
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	225,000,000	225,000,000
Common stock, issued shares	82,681,711	82,679,922
Common stock, outstanding shares	82,681,711	82,679,922