Fair Value Measurements - Carrying Amount and Estimated Fair Values of Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value Disclosures [Abstract]
Cash and cash equivalents, carrying amount	$ 86,709	$ 109,857	$ 33,412	$ 40,813
Interest rate swaps, carrying amount	(11,440)	(4,811)
Long-term debt, carrying amount	1,712,099	1,859,511
Cash and cash equivalents, fair value	86,709	109,857
Interest rate swaps, fair value	(11,440)	(4,811)
Long-term debt, fair value	$ 1,675,760	$ 1,846,181