Stockholders' Equity - Summary of Estimated Earned Payout (Detail)	12 Months Ended
	Dec. 31, 2016
2016 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimated Payout on Adjusted EBITDA	100.00%
Estimated Payout on TSR	100.00%
Estimated Payout Combined	100.00%
2015 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimated Payout on Adjusted EBITDA	100.00%
Estimated Payout on TSR	168.00%
Estimated Payout Combined	124.00%
2014 Three-year PSU Awards [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Estimated Payout on Adjusted EBITDA	200.00%
Estimated Payout on TSR	188.00%
Estimated Payout Combined	196.00%