Cash Dividends (Summary of Conversion Rates for Convertible Notes) (Detail) (USD $)	3 Months Ended
	Jun. 30, 2013
Series 2012 Notes [Member]
Debt Instrument [Line Items]
Conversion Rate per $1,000 Principal Amount (in Ratio)	176.389
Approximate Conversion Price Per Common Share (in Dollars per Share)	$ 5.67
Effective Date (Date)	Jun. 03, 2013
May 2015 Notes [Member]
Debt Instrument [Line Items]
Conversion Rate per $1,000 Principal Amount (in Ratio)	154.4189
Approximate Conversion Price Per Common Share (in Dollars per Share)	$ 6.48
Effective Date (Date)	Jun. 03, 2013
February 2015 Notes [Member]
Debt Instrument [Line Items]
Conversion Rate per $1,000 Principal Amount (in Ratio)	176.389
Approximate Conversion Price Per Common Share (in Dollars per Share)	$ 5.67
Effective Date (Date)	Jun. 06, 2013