Stock-Based Compensation Stock Options (Tables)

12 Months Ended

Mar. 31, 2017

Share-based Compensation Arrangement by Share-based Payment Award

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

Exercise Price Range	Option Shares Outstanding	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Life (in years)
$ 14.81 - $ 25.00	473	$	23.68	3.10
25.01 - 35.00	1,990	31.70		4.74
35.01 - 55.18	2,130	47.39		5.28
	4,593

Exercise Price Range	Option Shares Exercisable	Weighted-Average Exercise Price Per Share
$ 14.81 - $ 25.00	473	$	23.68
25.01 - 35.00	1,240	31.94
35.01 - 55.18	975	44.49
	2,688

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

	Years Ended March 31,
	2017		2016		2015
Stock options	$	8,347	$	9,403	$	11,584
Restricted stock and restricted stock units	52,049		52,670		45,975
Employee stock purchase plan	696		729		673
Affiliate management equity plans	26,566		26,184		5,206
Non-employee director awards	1,400		1,150		1,550
Performance share units	3,924		2,766		1,056
Employee stock trust	26		25		201
Total stock-based compensation expense	$	93,008	$	92,927	$	66,245

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

	Number of Shares		Weighted-Average Exercise Price Per Share
Options outstanding at March 31, 2014	4,801		$	43.02
Granted	918		47.65
Exercised	(694	)	30.75
Canceled/forfeited	(593	)	90.31
Options outstanding at March 31, 2015	4,432		39.58
Granted	876		54.51
Exercised	(349	)	28.35
Canceled/forfeited	(453	)	88.06
Options outstanding at March 31, 2016	4,506		38.48
Granted	753		31.31
Exercised	(313	)	27.66
Canceled/forfeited	(353	)	37.13
Options outstanding at March 31, 2017	4,593		$	38.15

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of Shares		Weighted-Average Grant Date Fair Value
Options unvested at March 31, 2016	1,962		$	11.48
Granted	753		31.31
Vested	(759	)	41.57
Canceled/forfeited	(51	)	47.13
Options unvested at March 31, 2017	1,905		$	42.54

Management [Member]

Share-based Compensation Arrangement by Share-based Payment Award

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

	Years Ended March 31,
	2017		2016		2015
Expected dividend yield	1.45	%	1.18	%	1.04	%
Risk-free interest rate	1.25	%	1.44	%	1.51	%
Expected volatility	30.95	%	24.37	%	29.53	%
Expected life (in years)	5.02		4.97		4.94

Chief Executive Officer [Member]

Share-based Compensation Arrangement by Share-based Payment Award

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

Expected dividend yield	1.48	%
Risk-free interest rate	0.86	%
Expected volatility	44.05	%

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		2015
Expected dividend yield	2.87	%	1.46	%	1.33	%
Risk-free interest rate	0.89	%	0.86	%	0.75	%
Expected volatility	25.99	%	22.63	%	30.81	%