Debt and Financing Arrangements - Summary of Recognized Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Debt Instrument [Line Items]
Total interest expense	$ 1,517	$ 1,526
Credit Facility [Member]
Debt Instrument [Line Items]
Total interest expense	$ 1,517	1,520
2006 Convertible Senior Subordinated Notes [Member]
Debt Instrument [Line Items]
Total interest expense		$ 6