Stock-Based Compensation - Summary of Restricted Stock Units (Detail)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-Vested Shares, Beginning Balance (in shares) | shares	1,304,271
Non-Vested Shares, Awarded (in shares) | shares	712,841
Non-Vested Shares, Vested (in shares) | shares	(513,073)
Non-Vested Shares, Cancelled/forfeited (in shares) | shares	(163,664)
Non-Vested Shares, Ending Balance (in shares) | shares	1,340,375
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Beginning Balance (in dollars per share) | $ / shares	$ 38.71
Weighted Average Grant Date Fair Value, Awarded (in dollars per share) | $ / shares	27.16
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	39.93
Weighted Average Grant Date Fair Value, Cancelled/forfeited (in dollars per share) | $ / shares	38.57
Weighted Average Grant Date Fair Value, Ending Balance (in dollars per share) | $ / shares	$ 32.11