Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common stock Voting	Additional Paid In Capital	Accumulated Other Comprehensive Income (Loss)	Treasury stock	Retained Earnings
Beginning Balance at Mar. 31, 2014	$ 409,161	$ 50	$ 273,574	$ 2,772	$ (117,802)	$ 250,567
Beginning Balance (in shares) at Mar. 31, 2014		49,922,959			8,757,175
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	61,192					61,192
Unrealized net investment gains (losses)	(12)			(12)
Unrealized net gains (losses) on derivative financial instruments	(1,094)			(1,094)
Cumulative translation adjustments	(6,311)			(6,311)
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	0
Issuance of common stock pursuant to exercise of options	$ 139	$ 0	139
Issuance of common stock pursuant to exercise of options (in shares)	23,850	23,850
Issuance of common stock pursuant to vesting of restricted stock units	$ 1	$ 1
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		728,239
Stock-based compensation expense for restricted stock units granted to employees	15,685		15,685
Issuance of common stock under employee stock purchase plan	5,889		5,889
Issuance of common stock under employee stock purchase plan (in shares)		137,500
Repurchase of treasury stock	(51,714)				$ (51,714)
Repurchase of treasury stock (in shares)					1,247,568
Excess tax benefit from share-based compensation awards	2,814		2,814
Ending Balance at Mar. 31, 2015	435,750	$ 51	298,101	(4,645)	$ (169,516)	311,759
Ending Balance (in shares) at Mar. 31, 2015		50,812,548			10,004,743
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(28,369)					(28,369)
Unrealized net investment gains (losses)	3			3
Unrealized net gains (losses) on derivative financial instruments	1,063			1,063
Cumulative translation adjustments	1,446			1,446
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	$ 632			632
Issuance of common stock pursuant to exercise of options (in shares)	0
Issuance of common stock pursuant to vesting of restricted stock units	$ 1	$ 1
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		736,170
Stock-based compensation expense for restricted stock units granted to employees	26,609		26,609
Issuance of common stock under employee stock purchase plan	10,560		10,560
Issuance of common stock under employee stock purchase plan (in shares)		447,252
Repurchase of treasury stock	(311,850)				$ (311,850)
Repurchase of treasury stock (in shares)					10,402,402
Issuance of shares related to the Comms Transaction	2,305,611	$ 62	2,305,549
Issuance of shares related to the Comms Transaction (in shares)		62,499,644
Excess tax benefit from share-based compensation awards	1,926		1,926
Ending Balance at Mar. 31, 2016	2,443,382	$ 114	2,642,745	(1,501)	$ (481,366)	283,390
Ending Balance (in shares) at Mar. 31, 2016		114,495,614			20,407,145
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	33,291					33,291
Unrealized net investment gains (losses)	(59)			(59)
Unrealized net gains (losses) on derivative financial instruments	(54)			(54)
Cumulative translation adjustments	(1,000)			(1,000)
Recognition of actuarial net gains (losses) from pension and other post-retirement plan	$ (858)			(858)
Issuance of common stock pursuant to exercise of options (in shares)	0
Issuance of common stock pursuant to vesting of restricted stock units	$ 2	$ 2
Issuance of common stock pursuant to vesting of restricted stock units (in shares)		950,159
Stock-based compensation expense for restricted stock units granted to employees	36,449		36,449
Issuance of common stock under employee stock purchase plan	15,697		15,697
Issuance of common stock under employee stock purchase plan (in shares)		471,658
Repurchase of treasury stock	(89,555)				$ (89,555)
Repurchase of treasury stock (in shares)					3,468,998
Shortfall from share-based compensation awards	(1,045)		(1,045)
Ending Balance at Mar. 31, 2017	$ 2,436,250	$ 116	$ 2,693,846	$ (3,472)	$ (570,921)	$ 316,681
Ending Balance (in shares) at Mar. 31, 2017		115,917,431			23,876,143