Stock-Based Compensation Stock Options (Tables)

9 Months Ended

Dec. 31, 2017

Share-based Compensation Arrangement by Share-based Payment Award

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Three Months Ended December 31,				Nine Months Ended December 31,
	2017		2016		2017		2016
Stock options	$	1,656	$	2,084	$	5,801	$	6,368
Restricted stock and restricted stock units	11,853		12,509		41,941		39,823
Employee stock purchase plan	109		110		502		527
Affiliate management equity plans	776		818		2,328		21,134
Non-employee director awards	200		—		1,275		1,150
Performance share units	870		1,032		3,134		2,901
Employee stock trust	7		6		21		19
Total stock-based compensation expense	$	15,471	$	16,559	$	55,002	$	71,922

Share-based Compensation Arrangements by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding [Table Text Block]

	Nine Months Ended December 31,
	2017				2016
	Number of Shares		Weighted-Average Exercise Price Per Share		Number of Shares		Weighted-Average Exercise Price Per Share
Options outstanding at March 31	4,593		$	38.15	4,506		$	38.48
Granted	421		37.64		753		31.31
Exercised	(378	)	29.45		(128	)	27.80
Canceled/forfeited	(102	)	47.07		(333	)	36.62
Options outstanding at December 31	4,534		$	38.63	4,798		$	37.77

Management [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Assumptions used to determine the weighted-average fair value of option grants

	Nine Months Ended December 31,
	2017		2016
Expected dividend yield	1.70	%	1.45	%
Risk-free interest rate	1.89	%	1.25	%
Expected volatility	26.79	%	30.95	%
Expected life (in years)	5.09		5.02

Key Employees [Member]

Share-based Compensation Arrangement by Share-based Payment Award

Assumptions used to determine the weighted-average fair value of option grants

	2017		2016
Expected dividend yield	2.96	%	2.87	%
Risk-free interest rate	1.47	%	0.89	%
Expected volatility	27.73	%	26.01	%