XML 68 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
0.25% Convertible Senior Notes, Convertible Note Hedge and Warrant - Schedule of Interest Expense (Detail) - 0.25% Convertible Senior Notes Due 2022 [Member]
$ in Thousands
3 Months Ended
Mar. 31, 2018
USD ($)
Debt Instrument [Line Items]  
Contractual interest expense $ 250
Amortization of debt discount 4,567
Amortization of issuance costs 341
Total interest expense $ 5,158