Convertible and Long-Term Debt Obligations - Credit Agreement - Additional Information (Detail) - Credit Agreement [Member] - Syndicate of Banks [Member] - Revolving Credit Facility [Member]	1 Months Ended
	Jun. 30, 2015
Federal Funds Purchased
Debt Instrument [Line Items]
Line of credit, additional interest rate	0.50%
LIBOR [Member]
Debt Instrument [Line Items]
Line of credit, additional interest rate	1.00%
Undrawn amounts interest rate [Member]
Debt Instrument [Line Items]
Line of credit, additional interest rate	0.25%