Summary of Significant Accounting Policies - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash paid:
Interest paid (net of amounts capitalized)	$ 16,749	$ 17,103	$ 19,744
Income taxes paid	105	23,553	390
Cash received:
Income taxes refund	7,768	0	388
Noncash investing and financing activities:
Acquisition of fixed assets included in accounts payable and accrued expenses	$ 2,031	$ 4,822	$ 5,789