Industry Segment and Geographic Area Data (Table Text Block)	3 Months Ended	9 Months Ended
	Dec. 31, 2021	Dec. 31, 2021
Geographic Areas, Long-Lived Assets [Abstract]
Industry Segment and Geographic Area Data	United States   Canada   Consolidated     (Unaudited)     (All amounts are in thousands of U.S. $'s) Quarter Ended December 31, 2021             Total revenues $ 1,334,131 $ 70,205 $ 1,404,336 Depreciation and amortization, net of (gains) on disposal   110,383   2,277   112,660 Interest expense   43,140   902   44,042 Pretax earnings   360,449   10,997   371,446 Income tax expense   87,135   2,845   89,980 Identifiable assets   16,077,571   510,507   16,588,078               Quarter Ended December 31, 2020             Total revenues $ 1,114,816 $ 55,166 $ 1,169,982 Depreciation and amortization, net of (gains) on disposal   158,844   1,454   160,298 Interest expense   41,378   750   42,128 Pretax earnings   233,163   8,408   241,571 Income tax expense   56,237   2,349   58,586 Identifiable assets  14,020,573   426,732   14,447,305	United States   Canada   Consolidated     (Unaudited)     (All amounts are in thousands of U.S. $'s) Nine Months Ended December 31, 2021             Total revenues $ 4,307,322 $ 234,124 $ 4,541,446 Depreciation and amortization, net of (gains) on disposal   379,989   1,802   381,791 Interest expense   119,856   2,909   122,765 Pretax earnings   1,320,056   45,016   1,365,072 Income tax expense   317,057   11,476   328,533 Identifiable assets   16,077,571   510,507   16,588,078               Nine Months Ended December 31, 2020             Total revenues $ 3,318,854 $ 163,273 $ 3,482,127 Depreciation and amortization, net of (gains) on disposal   471,592   7,424   479,016 Interest expense   120,015   2,159   122,174 Pretax earnings   685,312   21,596   706,908 Income tax expense   163,644   6,188   169,832 Identifiable assets  14,020,573   426,732   14,447,305