Debt Convertible Senior Notes Textual -Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) d $ / shares	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2014 USD ($)	Dec. 08, 2014 USD ($)
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt		$ 421,000
Interest Expense, Debt	$ 2,800,000
Amortization of debt discount (premium)	1,400,000
Interest Expense, Debt, Excluding Amortization	1,400,000
Repayments of Convertible Debt	0	$ 4,459,000
Convertible Debt [Member] | Senior 3 Point 25 Percent Convertible Notes Due 2020 [Member]
Debt Instrument [Line Items]
Gains (Losses) on Extinguishment of Debt	$ 400,000
Convertible Senior Notes, face amount				$ 172,500,000.0
Senior Credit Facility, applicable margin	3.25%
Debt issuance cost				5,100,000
Deferred financing costs				$ (4,200,000)
Remaining amortization period of discount on the liability component	3 years 9 months		4 years	6 years
Adjustments to additional paid in capital	$ 900,000
Convertible Senior Notes, conversion ratio	31.1891
Convertible Senior Notes, conversion price (in usd per share) | $ / shares	$ 32.06
Convertible Senior Notes, threshold trading days | d	20
Convertible Senior Notes, threshold consecutive trading days	30 days
Convertible Senior Notes, threshold percentage of stock price trigger	130.00%
Convertible Senior Notes, threshold consecutive business days	5 days
Convertible Senior Notes, threshold consecutive trading days, following consecutive business days	5 days
Convertible Senior Notes, threshold percentage of stock price trigger, following consecutive business days	98.00%
Convertible Senior Notes, observation period	25 days
Interest Expense, Debt	$ 2,800,000
Amortization of debt discount (premium)	1,400,000
Interest Expense, Debt, Excluding Amortization	$ 1,400,000
Debt Conversion, Converted Instrument, Rate	100.00%
Debt Instrument, Interest Rate, Effective Percentage	6.90%
Convertible Senior Notes, fair value disclosures				$ 141,900,000
Carrying value of equity component, net of issuance costs	$ 29,211,000		$ 29,211,000		$ 30,700,000
Repurchase of Convertible Debt	5,200,000
Repayments of Convertible Debt	4,500,000
Other Current Assets [Member] | Convertible Debt [Member] | Senior 3 Point 25 Percent Convertible Notes Due 2020 [Member]
Debt Instrument [Line Items]
Deferred financing costs	$ (2,589,000)		$ (2,753,000)