Industry Segment and Geographic Area Data	9 Months Ended
	Dec. 31, 2019
Segments, Geographical Areas [Abstract]
12. Industry Segment and Geographic Area Data	Industry Segment and Geographic Area Data     United States   Canada   Consolidated     (Unaudited)     (All amounts are in thousands of U.S. $'s) Quarter Ended December 31, 2019             Total revenues $ 886,731 $ 41,149 $ 927,880 Depreciation and amortization, net of (gains) losses on disposal   174,669   3,979   178,648 Interest expense   39,042   931   39,973 Pretax earnings (loss)   40,606   (277)   40,329 Income tax expense   9,303   94   9,397 Identifiable assets   12,575,914   418,408   12,994,322               Quarter Ended December 31, 2018             Total revenues $ 880,767 $ 38,324 $ 919,091 Depreciation and amortization, net of (gains) losses on disposal   147,868   2,259   150,127 Interest expense   34,051   776   34,827 Pretax earnings   100,832   2,190   103,022 Income tax expense   23,828   559   24,387 Identifiable assets   11,285,627   360,133   11,645,760       United States   Canada   Consolidated     (Unaudited)     (All amounts are in thousands of U.S. $'s) Nine Months Ended December 31, 2019             Total revenues $ 3,008,067 $ 149,276 $ 3,157,343 Depreciation and amortization, net of (gains) losses on disposal   471,535   10,006   481,541 Interest expense   115,523   2,460   117,983 Pretax earnings   411,565   8,832   420,397 Income tax expense   97,951   2,766   100,717 Identifiable assets   12,575,914   418,408   12,994,322               Nine Months Ended December 31, 2018             Total revenues $ 2,901,908 $ 141,267 $ 3,043,175 Depreciation and amortization, net of (gains) losses on disposal   416,784   4,335   421,119 Interest expense   102,924   2,187   105,111 Pretax earnings   472,302   15,577   487,879 Income tax expense   113,712   4,141   117,853 Identifiable assets   11,285,627   360,133   11,645,760