Equity - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Equity [Line Items]
Common stock issued in connection with business acquisitions	60,855
Reclassification of stock		$ 10,764,000
Number of shares held in treasury		0	0	0
Shares remaining under the current authorization repurchase program			3,411,416