Shareholders' Equity - AOCI Roll Forward (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the period	$ 26,957
Other comprehensive income before reclassifications	16,741
Amounts reclassified from cumulative other comprehensive income to net income	16
Net current period other comprehensive income	16,757
Balance at the end of the period	43,714
Unrealized Gain on Investment in Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the period	21,074
Other comprehensive income before reclassifications	12,142
Amounts reclassified from cumulative other comprehensive income to net income	0
Net current period other comprehensive income	12,142
Balance at the end of the period	33,216
Equity in Unrealized Gain of an Investee
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at the beginning of the period	5,883
Other comprehensive income before reclassifications	4,599
Amounts reclassified from cumulative other comprehensive income to net income	16
Net current period other comprehensive income	4,615
Balance at the end of the period	$ 10,498