Segment Information (Schedule Of Information For Revenues From External Customers By Destination And Long-Lived Assets Based On Physical Location) (Parenthetical) (Detail) (JPY ¥) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2010
Segment Reporting Information [Line Items]
Revenues from the United States	¥ 190,243	¥ 167,553	¥ 146,319