Schedule II - Valuation and Qualifying Accounts (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance At Beginning of Year	$ 627	$ 245	$ 228
Additions Charged to Operations	1,936	439	41
Deductions From Reserves	114	57	24
Balance At End of Year	2,449	627	245
Warranty [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance At Beginning of Year	2,329	1,525	2,279
Additions Charged to Operations	5,055	6,261	2,642
Deductions From Reserves	5,140	5,457	3,396
Balance At End of Year	2,244	2,329	1,525
Deferred Tax Asset Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance At Beginning of Year	63,881	36,395	21,783
Additions Charged to Operations	15,577	27,486	14,612
Deductions From Reserves	0	0	0
Balance At End of Year	79,458	63,881	36,395
Sales Returns and Allowances [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance At Beginning of Year	911	545	346
Additions Charged to Operations	196	497	911
Deductions From Reserves	380	131	712
Balance At End of Year	$ 727	$ 911	$ 545