Fair Value Measurements (Details 1) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets:
Equity securities	$ 29,125
Assets	29,169	$ 4,488
Liabilities:
Total liabilities		10,049
Rochester Royalty Obligation [Member]
Liabilities:
Fair value of derivative liability		9,287
Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	44
Liabilities:
Fair value of derivative liability	255	762
Equity Securities [Member]
Assets:
Equity securities	22,473	4,488
Fair Value, Inputs, Level 1 [Member]
Assets:
Assets	22,194	4,209
Liabilities:
Total liabilities		0
Fair Value, Inputs, Level 1 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Fair value of derivative liability	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Assets:
Equity securities	22,194	4,209
Fair Value, Inputs, Level 2 [Member]
Assets:
Assets	44	0
Liabilities:
Total liabilities		762
Fair Value, Inputs, Level 2 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Fair value of derivative liability		0
Fair Value, Inputs, Level 2 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	44
Liabilities:
Fair value of derivative liability	255	762
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets:
Equity securities	0	0
Fair Value, Inputs, Level 3 [Member]
Assets:
Assets	6,931	279
Liabilities:
Total liabilities		9,287
Fair Value, Inputs, Level 3 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Fair value of derivative liability		9,287
Fair Value, Inputs, Level 3 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Fair value of derivative liability	0	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets:
Equity securities	$ 6,931	$ 279