Noncontrolling interests roll forward (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance				$ 16,372					$ 16,372
Additions due to acquisition of controlling interest in ISSC										$ 52,467
Net loss attributable to noncontrolling interests	$ 0	$ 0	$ 0	(207)	$ (822)	$ (1,259)	$ (1,603)	$ 0	(207)	(3,684)	$ 0
Other comprehensive loss attributable to noncontrolling interests									0	(866)	0
Purchase of additional interests									(18,051)	(32,095)
Balance	0				16,372				0	16,372
Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Balance				$ 16,372				$ 0	16,372	0
Additions due to acquisition of controlling interest in ISSC										52,467
Net loss attributable to noncontrolling interests									(207)	(3,684)
Other comprehensive loss attributable to noncontrolling interests										(866)
Purchase of additional interests									(16,165)	(31,849)
Other										304
Balance	$ 0				$ 16,372				$ 0	$ 16,372	$ 0