Common Stock (SBC) (Details) - USD ($)		1 Months Ended					12 Months Ended		17 Months Ended
	Jun. 30, 2014	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2015	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Aug. 31, 2015
Stock repurchases
Authorized amount										$ 100,000,000
Treasury stock shares acquired (in shares)									3,342,035
Treasury stock value acquired							$ 12,953,453	$ 20,943,816	$ 33,700,000
Restricted stock awards
Common stock
Shares granted to officers under the equity incentive plan	655,000				250,000	274,000	284,708
Non-executive director | Restricted stock awards
Common stock
Shares granted to officers under the equity incentive plan		5,995	8,695	10,130	6,950
Non-employee consultant | Restricted stock awards
Common stock
Shares granted to officers under the equity incentive plan		1,199	1,739