Stockholders' Equity Restricted Stock Unit Activity (Details)	12 Months Ended
	Mar. 31, 2018 $ / shares shares	Mar. 31, 2017 $ / shares shares	Mar. 31, 2016 $ / shares shares	Mar. 31, 2015
Stockholders Equity Restricted Stock Unit Activity Details
Balance at beginning of period | shares	4,939,050	4,544,799	2,698,686
Granted | shares	3,481,870	2,491,877	2,681,997
Vested | shares	(1,833,038)	(1,600,831)	(589,788)
Forfeited | shares	(652,339)	(496,795)	(246,096)
Balance at end of period | shares	5,935,543	4,939,050	4,544,799
RSU weighted-average remaining contractual term, in years	1.60	1.55	1.67	1.88
Beginning of period, weighted-average purchase price | $ / shares	$ 11.57	$ 8.08	$ 7.33
Granted, weighted-average purchase price | $ / shares	14.41	15.15	8.78
Vested, weighted-average purchase price | $ / shares	10.27	7.89	7.79
Forfeited, weighted-average purchase price | $ / shares	12.73	9.56	8.15
End of period, weighted-average purchase price | $ / shares	$ 13.51	$ 11.57	$ 8.08