Geographic Areas and Product Sales - Net Sales by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 60,057	$ 46,419	$ 58,310	$ 39,318	$ 52,092	$ 36,319	$ 46,651	$ 34,410	$ 204,104	$ 169,472	$ 141,481
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									195,613	162,263	136,973
CANADA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									$ 8,491	$ 7,209	$ 4,508